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REESE    LIBRARY 

OP   THK 

UNIVERSITY   OF  CALIFORNIA. 

Received . 


THE 

BERMUDA  ISLANDS: 

A  CONTRIBUTION  TO   THE  PHYSICAL  HISTORY  AND  ZOOLOGY 

OF    THE 

SOMERS  ARCHIPELAGO. 

WITH  AN  EXAMINATION  OF  THE  STRUCTURE  OF  CORAL  REEFS. 


BESEAECHES  UNDERTAKEN  UNDEB  THE  AUSPICES  OF  THE  ACADEMY  OF 
NATUBAL  SCIENCES  OF  PHILADELPHIA. 


BY 

ANGELO   HEILPRIN,  FG.S.A.,F.A.GEOGR.  soc., 

Curator-in-Charge  of,  and   Professor  of  Invertebrate  Paleontology  at,  the  Academy  of 

Natural  Sciences  of  Philadelphia;     Professor  of  Geology  at  the  Wagner  Free 

Institute  of  Science;     Member  of  the  American  Philosophical  Society,  etc. 


WITH  ADDITIONS  BY 

Prof.  J.  PLAYFAIR  McMuRRicn,  Mr.  H.  A.  PILSBRY,  Dr.  GEORGE 
MARX,  Dr.  P.  R.^flf3sRr5M-Mr.  C.  H.  BOLLMAN. 


PHILA 

PUBLISHED  BY  THE  AUTHOR. 

ACADEMY  OF  NATURAL  SCIENCES. 
1889. 


BIOLOGY 

LIBRARY 

G 


COPYRIGHT,  1889,  BY  A    HEILPRIN 


prsss  op 
BINDER  &  KELLY, 

Printers  and  Publishers, 


THE  observations  recorded  in  the  following  pages  arc  the 
outcome  of  a  vacation-journey  undertaken  in  the  summer  of 
1888  in  company  with  a  class  of  students  from  the  Academy 
of  Natural  Sciences  of  Philadelphia.  My  main  object  in  visit- 
ing the  islands  was  to  satisfy  my  mind  on  certain  points  con- 
nected with  the  structure  and  physiognomy  of  coral  reefs,  to 
the  study  of  which  the  Bermudas  offer  special  advantages.  I 
contemplated  but  little  work  in  zoology,  and  that  which  was 
accomplished  may  be  considered  supplemental  to  the  plan  of 
work  originally  laid  out.  It  was  not  until  my  return  to  Phil- 
adelphia that  I  was  made  aware  of  the  extent  of  the  zoological 
material  collected  by  us,  and  how  little  systematic  study  of  the 
fauna  of  the  region  had  been  made  prior  to  our  visit.  Some 
of  our  material  still  awaits  examination ;  for  the  elaboration 
of  that  portion  which  is  delineated  in  the  present  volume  I 
am  largely  indebted  to  the  labors  of  a  number  of  specialists 
who  have  kindly  volunteered  their  assistance.  In  this  connection 
I  desire  to  acknowledge  my  indebtedness  to  Prof.  J.  Play  fair 


McMurrieh,  formerly  of  Haverford  College;  to  Mr.  H.  A 
Pilsbry,  of  the  Academy  of  Natural  Sciences ;  to  Dr.  George 
Marx,  of  Washington;  to  Dr.  P.  R.  Uhler,  of  Baltimore;  to 
the  late  Mr.  C.  H.  Bollman,  of  Bloomington,  Ind.;  and  to  two 
of  my  immediate  assistants,  Messrs.  J.  E.  Ives  and  Witmer 
Stone. 

To  Miss  A.  Peniston,  of  Peniston's,  Bermuda,  I  am  under 
special  obligation  for  the  use  of  much  new  material  illustrating 
the  Bermudian  fauna ;  and  I  am  similarly  indebted  to  Dr.  W.  H. 
Dall,  of  the  U.  S.  National  Museum,  Washington,  for  having 
placed  at  my  disposition  the  collection  of  Bermuda  shells  made 
a  few  years  ago  by  Mr.  G.  Brown  Goode. 

Finally,  I  desire  to  convey  my  thanks  to  the  members  of 
my  class — Messrs.  J.  E.  Ives,  Witmer  Stone,  Roberts  Le  Bou- 
tillier;  Misses  Emma  Walter,  Mary  A.  Schively,  Virginia 
Maitland,  Emily  G.  Hunt,  Ella  Hunt — all  of  whom  rendered 
much  valuable  assistance  either  in  the  field  or  in  the  labora- 
tory. 

A.  H. 

ACADEMY  OF  NATURAL  SCIENCES, 

Philadelphia,  September,  i88q. 


CONTENTS. 

I.  The  Bermuda  Islands.     General  Impressions.     .     .       1 

II.  The  Outer  Reef. '.......     15 

III.  Physical  History  and  Geology 23 

IV.  The  Coral-Reef  Problem 48 

V.  Relationship  of  the  Bermudian  Fauna 78 

VI.  Zoology  of  the  Bermudas 97 

VII.  Zoology  (continued) 136 

VIII.  Zoology  (Arthropoda). 146 

IX.  Zoology  (Mollusca) 166 

X.  Notes  on  the  Literature  of  Coral  Reefs 202 

Results  of  Geological  Observations.    ....'..     46 
Summary  of  Observations  on  the  Berrnudian  Fauna     95 


CORRECTIONS. 


40.  For  "  perspicuity  ",  sixth  line  from  top,  rea  1  perspicacity. 
58.  In  place  of  the  words  "  more  rapid",  third  line  from  top,  substitute  greater. 
102.  For  "  pediculate",  eighth  line  from  bottom,  re  id  pedicellate. 


I. 


THE  BERMUDA  ISLANDS. 


My  first  impression  of  the  Bermudas  was  one  of  disappoint- 
ment. I  had  heard  so  much  of  the  "  hundred  islands,"  of  the 
luxuriant  vegetation,  that  I  found  it  difficult  to  realize  that 
these  undulating  hills,  rising  in  their  garb  of  withered  green, 
were  in  reality  the  far-famed  pearl  of  the  Atlantic.  But  our 
visit  was  timed  for  the  month  of  July,  and  possibly  the  withered 
condition  of  the  vegetation  had  something  to  do  with  this 
feeling  of  disappointment.  The  clumps  of  palmettos  which  are 
bunched  against  the  hillsides  were  as  yet  undistinguishable, 
and  the  eye  rested  on  a  monotonous  expanse  of  dirty  green,  re- 
lieved here  and  there  by  dark  masses  of  the  Bermuda  juniper, 
which,  from  a  distance,  recalled  the  cloud-shadowed  patches  of 
our  northern  mountain  slopes.  Innumerable  particles  of 
white  cottages  gleamed  forth  in  the  bright  sunlight,  but  their 
uniform  brilliancy  only  served  to  intensify  the  sombreness  of 
the  background  which  they  illumined. 

I  had,  from  assumed  geological  knowledge,  expected  to  see 
a  long  white  crest  rolling  over  the  outer  reef,  but  in  this  ex- 
pectation I  was  also  disappointed.  We  were  being  carried  in 
on  the  flood,  and  no  trace  of  this  natural  parting  of  the  waters 


2  THE  BERMUDA  ISLANDS. 

was  visible.  As  we  approached  nearer  to  the  shore,  however, 
abrupt  changes  in  the  color  of  the  water  revealed  the  position 
of  the  coral-shallows,  but  we  as  yet  saw  nothing  of  the  reef  of 
the  imagination.  Occasional  jelly-fishes  floated  lazily  by,  and 
the  ever  merry  petrels  were  still  quivering  in  our  path  of 
beaten  foam.  Our  first  tropic-bird  hovered  about  the  rigging, 
seemingly  surprised  at  the  early  intrusion  which  we  had  per- 
mitted ourselves.  The  flying-fishes  became  more  numerous  as 
we  neared  the  islands,  and  they  could  be  frequently  seen  skip- 
ping away  five  or  more  at  a  time,  and  usually  in  a  direction  at 
right  angles  to  the  line  of  the  ship. 

I  was  anxious  to  determine  the  true  nature  of  their  aerial 
locomotion,  and  'to  settle  the  vexed  question  of  the  supposed 
flying  movements  of  the  fins.  We  accordingly  watched  these 
interesting  creatures  very  intently,  and  followed  them  with  our 
glasses  over  their  entire  course.  So  rapid  was  their  motion, 
however,  that  it  was  not  easy  to  keep  them  within  the  field 
of  the  glass,  and  still  less  easy  to  hold  them  in  distinct  vision, 
and  for  a  long  time  we  really  hardly  knew  what  we  saw. 
We  failed,  however,  to  detect  any  positive  continuous  move- 
ment on  the  part  of  the  fins,  and  it  certainly  appeared  as 
though  in  all,  or  nearly  all,  cases  the  animal  merely  shot 
forward  as  the  result  of  some  primary  impetus,  taking  a 
course  nearly  horizontal  with  the  surface  of  the  water. 
This  direct  course,  in  view  of  the  apparent  method  of  pro- 
pulsion, was  certainly  surprising,  as  it  would  naturally  be 
expected  that  from  an  initial  leap  the  line  of  travel  would  be 
that  of  a  regular  curve.  But  the  horizontal  course  was  pos- 
sibly more  apparent  than  real.  At  intervals,  two  or  three  times 
in  a  single  flight,  the  animal  seemed  to  strike  the  crest  of  a 
wave,  and  acquire  new  impetus  from  a  blow  of  the  tail.  In 
this  way  the  flight  may  be  said  to  be  one  of  distinct  passages 
— although  without  arrest  of  movement — in  which  the  curve 
motion  largely  disappears,  or  is  at  least  reduced  to  its  lowest 
terms.  Indeed,  the  successional  character  of  the  flight  could  be 
plainly  seen  in  the  sudden  jerky  changes  of  direction  which 


GENERAL  INPRESSIONS.  3 

were  marked  off  at  irregular  intervals,  and  at  points  where  rising 
waves  apparently  met  the  supplemental  strokes  of  the  tail. 
The  duration  of  flight  was  from  five  to  eleven  or  twelve  seconds, 
while  the  distance  covered  was  probably,  in  extreme  cases,  not 
less  than  200-300  feet,  and  possibly  even  more. 

The  inner  waters  of  the  reef  showed  those  remarkable  con- 
trasts of  color  which  have  been  so  frequently  dwelt  upon  and 
depicted  by  travelers.  From  the  most  intense  indigo  we  pass 
abruptly  to  a  brilliant  emerald,  and  from  this  again  possibly 
to  a  bright  sea-green.  So  sudden  are  the  transitions  that  the 
semblance  of  a  natural  water  is  largely  destroyed,  and  for  a 
moment  one  feels  inclined  to  doubt  the  reality  of  the  scene 
before  him.  I  must  confess  that  had  I  been  informed  in  ad- 
vance of  these  wonderful  chromatic  effects,  I  should  have  been 
loud  in  pronouncing  the  impossibility  of  their  occurrence,  so 
wholly  unnatural  did  they  appear. 

Passing  through  the  line  of  old  hulks,  whose  grass-grown 
bottoms  and  battered  planks  emphasized  the  words  of  condem- 
nation which  relegated  the  ancient  merchantmen  to  the  rank 
of  objets  d'  art,  we  entered  the  harbor  of  Hamilton.  The  fact 
of  its  being  Sunday  did  not  obtrude  itself  upon  the  throng  that 
had  assembled  to  greet  us  on  our  arrival.  The  helmeted  red- 
coat and  servant,  custom-house  officials  and  steamship  agents 
were  out  in  force,  but  they  were  far  outnumbered  by  that  class 
of  easy-going  inhabitants  whose  hardest  labor  appears  to  be 
that  of  doing  nothing.  The  time-honored  custom  of  building 
connecting  gang-planks  instead  of  bringing  the  ship  close  up 
to  the  wharf,  delayed  our  debarkation  by  about  a  half-hour,  but 
delays  of  this  or  a  similar  kind,  as  we  soon  discovered,  are  of 
little  moment  with  the  Bermudians. 

The  capital  city,  Hamilton,  has  little  of  interest  to  detain  the 
stranger  beyond  the  beautiful  display  of  exotic  plants  which 
are  to  be  found  in  the  private  gardens.  The  broad  and  pleas- 
ant avenues  which  intersect  the  town  at  nearly  right  angles, 
and  glisten  with  that  intensity  of  which  only  a  white  lime- 
stone is  capable,  possess  the  general  features  of  the  ordinary 


4  THE  BERMUDA  ISLANDS. 

country  roads,  setting  firm  and  hard  under  almost  all  condi- 
tions of  weather  and  temperature.  They  rarely  require  repair- 
ing, and  their  even  compactness  well  sustains  the  quality  for 
which  the  Bermudian  roads  are  famous.  Rain  affects  them  but 
little,  except  in  so  far  as  it  assists  as  a  solidifier,  and  a  few 
moments  after  a  heavy  shower  they  are  generally  as  pass- 
able as  after  prolonged  exposure  to  the  sun.  Here  and  there 
extensive  villas  and  gardens  betray  opulence,  but  more  com- 
monly it  is  the  appearance  of  pleasurable  comfort  rather  than 
the  possession  of  riches  which  appeals  to  the  eye  of  the  visitor. 
The  recessed  house-fronts,  opening  upon  broad,  shaded  veran- 
das, typifv  a  style  of  architecture  doubtless  best  adapted  to 
the  requirements  of  the  climate,  while  the  dazzling  whiteness 
of  the  exteriors  emphasizes  an  amount  of  attention  bestowed 
upon  house-decoration  which  would  probably  surprise  even 
the  proverbially  neat  cottagers  of  rural  Belgium  and  Holland. 
We  were  informed  that  the  operation  of  whitewashing  was  re- 
sorted to  as  often  as  twice  a  year,  and  where,  as  is  almost  uni- 
versally the  case  throughout  the  island  group,  the  drinking 
water  is  collected  as  off-flows  from  the  roof,  this  part  of  the  house 
is  anointed  as  well  as  the  sides.  At  intervals  throughout  the 
town,  as  also  in  the  country,  extensive  inclined  basins  have 
been  constructed  for  the  reception  of  rain-water,  and  serve 
as  reservoirs  for  periods  of  emergency. 

The  shops  are  in  the  main  not  attractive,  and  on  the  whole 
they  betray  a  lack  of  energy  in  their  management  which  is 
surprising  in  a  region  so  largely  visited  by  strangers.  We 
were  recommended  to  a  presumably  fashionable  confectioner's, 
the  floor-space  in  whose  establishment  was  given  up  in  large 
part  to  a  display  of  hats  and  clothing,  and  the  walls  to  musical 
instruments.  In  another  large  establishment  it  was  reported 
that  anything  could  be  obtained  from  a  coffin  to  a  pulpit,  but 
we  found  it  impossible  to  procure  an  ordinary  insect  net;  nor 
were  we  better  rewarded  as  far  as  this,  to  us  necessary,  article 
was  concerned,  by  inquiry  elsewhere. 

As  before  remarked,  the  attractive  feature  of  the  town  is  to 


GENERAL  IMPRESSIONS.  5 

be  found  in  the  display  of  exotic  plants.  This  exhibit  is,  how- 
ever, not  confined  to  Hamilton  ;  it  is  the  property  of  the  entire 
island  group,  where  it  has  become,  if  the  expression  might  be 
permitted,  naturalized.  The  unfortunate  ones  among  us  who 
in  the  northern  region  ecstatically  wonder  at  the  rare  treats 
which  the  floriculturist  from  time  to  time  lays  before  them,  can 
obtain  but  little  comfort  from  a  trip  to  the  Bermudas.  Their 
earlier-formed  notions  of  grandeur  soon  disappear.  It  would, 
however,  be  conveying  a  false  impression  to  state  that  the  veg- 
etation is  luxurious,  or  that  it  is  at  all  comparable  in  exuber- 
ance with  the  vegetation  of  the  true  tropics,  or  even  with  that 
of  many  parts  of  the  peninsula  of  Florida.  On  the  contrary, 
it  is  on  the  whole  sparse,  and  only  here  and  there,  in  favored 
localities,  or  where  the  husbandman  has  largely  assisted  nature, 
does  it  reveal  those  touches  of  picturesque  quality  which  so 
impress  the  mind  of  the  stranger,  and  lead  him  to  believe  in 
special  luxuriance. 

The  native  arboreal  vegetation  is  scrubby,  consisting  almost 
wholly  of  the  Bermuda  juniper  and  the  sabal  or  palmetto,  the 
latter  being  probably  the  only  native  species  of  palm  of  the 
twelve  or  more  forms  now  found  on  the  islands.  The  date 
and  cocoa-nut  are  both  cultivated,  but  it  is  only  exceptionally 
that  the  fruit  arrives  at  maturity.  Superb  specimens  of  the 
former,  the  so-called  "three  sisters, "are  found  in  the  singularly 
attractive  public  garden  of  St.  George's,  but  elsewhere  the  tree 
is  not  exactly  uncommon,  rising  generally  in  solitary  grandeur 
above  its  less  pretentious  associates.  Nothing,  it  appears  to 
me,  can  surpass  in  majesty  the  five  specimens  of  cabbage-palm 
( Oreodo-jra  oleracea)  which  adorn  the  roadside  at  Pembroke  Hall, 
in  the  outskirts  of  Hamilton,  and  justly  constitute  the  pride  of 
the  Bermudians.  Like  granite  monoliths  the  gray  shafts,  GO- 
TO feet  in  height,  stand  unbending  to  the  elements  that  play 
about  them,  unmoved  by  the  force  that  tosses  their  delicate 
plumes  into  restless  activity. 

Of  our  common  deciduous  trees,  oaks,  birches,  beeches,  pop- 
lars, etc.,  there  is  sca-rcely  a  trace  to  be  seen,  nor  is  there  any- 


6  THE  BERMUDA  ISLANDS. 

thing  to  replace  them.  An  occasional  sycamore,  mulberry  or 
weeping-willow  still  reminds  one  of  the  temperate  north,  but 
beyond  these  and  the  Bermuda  juniper,  there  is  little  sugges- 
tive of  the  woods  barely  six  hundred  miles  distant.  The  uni- 
versality of  the  juniper,  however,  imparts  a  decidedly  north- 
ern aspect  to  the  vegetation,  despite  the  large  number  of  tropi- 
cal elements  that  are  embodied  in  it.  The  latter  are  too 
irregularly  scattered  to  constitute  dominating  factors  in  the 
modeling  of  the  landscape.  At  intervals  bits  of  delicious  tropi- 
cal nature  surprise  one ;  warm  and  sunshiny  patches  of  palm- 
land,  largely  overgrown  with  the  coarse  bracken,  and  bordered 
by  almost  impenetrable  thickets  of  banana  and  plantain,  fall 
refreshingly  upon  the  eye  that  has  perhaps  become  satiated 
with  the  juniper,  and  that  glory  of  the  Bermudas,  the  oleander. 
O'er  hill  and  dale,  far  and  near,  in  the  garden  and  along  the 
roadside,  this  superb  bush  scatters  its  fragrance  to  the  winds . 
For  one  who  has  not  seen  the  rose-flowered  oleander  in  its  na- 
tive home,  or  in  this  land  of  its  adoption,  it  is  impossible  to 
conceive  of  the  effect  which  is  produced  by  the  great  masses  of 
showy  blossoms  which  appear  here,  there,  and  everywhere 
throughout  the  landscape.  The  hedges  are  ablaze  with  their 
blossoms,  and  buried  in  perfume;  the  roadways  are  simi- 
larly bejeweled  and  scented.  I  can  only  compare  the  general 
effect  with  that  produced  by  our  copses  of  rhododendron,  but, 
while  the  flowers  and  foliage  of  the  oleander  suffer  as  individ- 
ual elements  in  the  comparison,  they  more  than  compensate 
by  their  masses. 

A  first  impression  of  a  country  drive  in  the  Bermudas, 
along  some  such  road  as  the  "middle  road"  leading  from 
Hamilton  to  Flatts  Village,  is  not  soon  forgotten.  The  gray, 
one  might  almost  say  omnipresent,  bounding  wall,  which 
forms  part  of  the  natural  rock  of  the  islands,  the  retired  and 
sheltered  cottages,  the  peculiar  inhabitants — more  black  than 
white — and  above  all  the  vegetation,  strike  one  as  strange  and 
novel.  Birds  of  bright  plumage,  the  red  cardinal  and  blue-bird? 
flit  numerously  before  you,  and  although  they  are  regular 


GENERAL  IMPRESSIONS.  7 

members  of  the  North  American  avifauna  as  well,  they  ap- 
pear here  in  a  different  light  than  with  us,  since  they,  with  the 
little  ground-dove,  form  the  most  noticeable,  if  not  the  domi- 
nating, elements  in  the  bird-fauna  of  the  islands.  We  are  in 
a  little  world  of  our  own,  distinct  from  either  Europe  or 
America. 

The  corn-fields  of  our  temperate  north  are  here  largely  re- 
placed by  fields  of  bananas  and  plantains,  which  are  grown  in 
dense  and  almost  impenetrable  thickets.  Although  at  first  at- 
tractive by  their  novel,  and  suggestively  tropical  appearance,  the 
eye  soon  wearies  of  the  gross  and  wind-rifted  leaves,  and  eagerly 
falls  upon  the  much  more  delicate  vegetation  of  the  bamboo, 
which  here  and  there  shoots  its  willowy  tufts  30  or  40  feet  into 
the  air.  The  cane  is  also  a  graceful  ornament  about  many  of 
the  country  cottages. 

The  banana  "  trees"  wrere  laden  with  fruit  at  the  time  of  our 
visit,  and  naturally  we  had  a  good  opportunity  to  judge  of  the 
merits  of  this  highly-prized  article  of  food  with  the  Bermu- 
dians.  At  breakfast,  dinner,  and  supper  it  was  a  constant 
accompaniment  of  the  table,  and  always  welcome.  The  fruit 
is  considerably  smaller  than  the  imported  article  with  us,  and 
decidedly  tastier  or  sweeter,  doubtless  due  to  its  being  picked 
fresh  from  the  plant.  The  more  commonly  cultivated  variety 
is  the  form  known  as  Musa  Cavendishi,  or  dwarf  banana,  which 
rarely  exceeds,  to  the  bend  or  apex  of  the  leaf,  more  than 
about  eight  feet  in  height;  it  always  presents  a  stubby  appear- 
ance, more  like  a  great  coarse  weed,  which  has  grown  up 
spontaneously,  than  a  cultivated  plant.  Indeed,  it  can  scarcely 
be  said  to  be  under  cultivation,  since  practically  no  attention  is 
paid  to  its  proper  growth  and  development;  nature  does  it  all. 
Bunches  of  fruit  weighing  fifty  pounds  or  more  are  no  rarity, 
and  occasionally  they  reach  nearly  double  this  weight. 

The  plantain,  which  is  more  rarely  seen,  and  whose  fruit  is 
not  held  in  popular  favor  as  an  article  of  food,  is  a  much  more 
graceful  and  imposing  plant,  with  leaves  eight  or  ten  feet, 
or  even  more,  in  length.  It  grows  to  more  than  twice  the 


8  THE  BERMUDA  ISLANDS. 

height  of  the  common  banana,  and,  although  its  leaves  are 
largely  wind-rifted,  it  never  presents  the  shabby  appearance  of 
the  latter. 

Among  the  other  distinctive  accompaniments  of  the  road- 
side are  the  aloe  and  yucca,  or  Spanish  bayonet.  The  flowering 
stems  of  the  former,  rising  twenty  or  twenty-five  feet  in  height, 
are  not  an  uncommon  feature  in  the  landscape  of  the  garden- 
tracts.  Of  the  fifteen  or  more  species  of  cactus  now  found  on 
the  islands,  some  of  which,  like  the  Turk's  cap,  or  melon  cac- 
tus, and  the  night-blooming  cereus,  are  extensively  cultivated 
in  the  gardens,  only  one,  the  prickly-pear  (Opuntia  vulgaris), 
can  be  said  to  be  at  all  common.  It  is  found  scattered  here 
and  there  about  the  sandy  wastes,  or  hanging  in  sprawling 
masses  from  the  road  walls.  Some  notion  of  the  luxuriance  of 
growth  may  be  had  from  the  condition  of  the  plants  of  the 
night-blooming  cereus.  Shortly  before  our  departure  from 
the  islands  we  were  hospitably  invited  to  visit  a  plant  of  this 
species  in  the  garden  of  a  Mrs.  Peniston,  just  outside  of  Flatts 
Village.  It  is  scarcely  necessary  to  say  that  we  were  surprised 
when  we  beheld  a  plant  covering  an  area  equal  to  that  of  a  fair- 
sized  room,  and  supporting  upwards  of  200  of  the  most  superb 
flowers!  Well  may  the  tourist  go  back  down-hearted  to  his 
native  conservatory. 

But  this  is  not  the  only  instance  where  a  comparison  be- 
tween home  and  foreign  products  may  give  rise  to  sad  reflec- 
tions. Alas,  how  sadly  changed  must  be  the  conception  of  a 
rubber-plant,  after  one,  who  had  hitherto  been  accustomed 
only  to  the  "wonders"  of  the  drawing-room  and  conservatory, 
has  seen  the  monster,  stretching  forth  its  arms  like  an  oak, 
at  "  Par  le  Ville,"  Hamilton ! 

If,  however,  the  eye  is  riveted  to  these  remarkable  forms  of 
vegetality,  it  meets  only  with  disappointment  when  it  scans 
the  usually  sparse  herbaceous  vegetation  of  the  woodlands,  or 
that  which  covers  the  open  meadows  and  rock-surfaces.  We 
look  in  vain  for  that  rich,  dense  green  which  forms  the  sunny 
undergrowth  of  our  forests,  for  the  crop  of  weed  and  grass  which 


GENERAL  IMPRESSIONS.  9 

is  the  wealth  of  our  fields  and  pastures.  Plenty  of  grasses 
there  are,  it  is  true,  but  they  are  in  most  places  thin  and  weak. 
Only  here  and  there  in  the  deep  and  open  hollows,  as  in  the 
neighborhood  of  the  "marshes,"  do  they  show  anything  like 
luxuriance  of  growth.  It  should,  however,  be  stated  that  in 
many  sheltered  limestone  hollows,  as  well  as  along  similarly 
protected  rock-ledges,  the  vegetation  is  wonderfully  profuse, 
interwoven  and  interrnatted  so  as  to  render  penetration  almost 
impossible.  The  coffee-tree  thicket  back  of  Joyce's  cave,  and 
the  convolvulus  cave  close  by,  are  wonderful  exhibitions  of  this 
kind;  and  likewise  the  tract  about  Walsingham.  But  over  the 
greater  part  of  the  island  one  may  sing  his  paaans  to  the  sage 
(Lantana),  wrhich  has  virtually  taken  possession  of  the  soil,  a 
not  very  attractive  nor  delightfully  odorous  plant. 

Our  headquarters  during  our  brief  stay  at  the  Bermudas 
were  at  the  Flatts  Village,  a  small  assortment  of  neat  houses 
and  cottages  situated  at  the  entrance  to  Harrington  Sound. 
A  strong  current  passes  here  at  high-water  into  the  inner  basin, 
bringing  in  much  sediment  from  the  open  sea,  and  with  it  a 
rich  assortment  of  animal  life.  The  low-water  sands  constitute 
one  of  the  best  collecting  grounds  of  the  archipelago,  excepting, 
of  course,  the  outer  reefs,  and  the  under  surface  of  almost  every 
stone  offered  something  for  our  collections.  We  were  fortunate 
to  discover  here  a  new  species  of  cuttle-fish  (Octopus  chromatus) 
characterized  by  unusually  attenuated  tentacles ;  but,  beyond 
two  other  individuals  of  another  species  which  we  failed  to  ob- 
tain, this  was  the  only  representative  of  this  order  of  animals 
with  which  we  came  in  contact  during  the  entirejourney.  Yet, 
they  are  said  yto  be  specially  abundant  just  among  the  rock 
crevices  of  Flatts  Inlet. 

It  is  wonderful  with  what  tenacity  these  animals  hold  on  to 
their  anchorages  when  a  forcible  attempt  is  made  to  eject  them 
from  their  shelters.  We  in  vain  tried  by  both  coaxing  and 
pulling  to  dislodge  one  of  these  interesting  creatures,  but,  de- 
spite the  havoc  made  by  chopping  the  enveloping  rock,  we 


10  THE  BERMUDA  ISLANDS. 

were  compelled  to  desist  from  our  attempt  after  the  labor  of  a 
full  hour  and  a  half.  The  chromatic  changes  of  the  skin  were 
at  times  very  rapid,  and  so  nicely  did  the  animal  adjust  its 
color  to  that  of  the  rock  as  to  render  its  outline  barely  visible. 
The  wonderful  transparency  of  the  greenish  waters  permitted 
objects  to  be  distinctly  visible  at  depths  of  20-25  feet,  and  where 
there  were  no  moving  ripples,  at  even  greater  depths.  I 
doubt  much,  however,  the  statement  that  under  ordinarily 
favorable  conditions  objects  may  be  distinguished  at  depths  of 
60  to  70  feet,  even  with  the  aid  of  the  water-glass  ;  at  any  rate, 
our  own  experience  failed  to  give  support  to  this  commonly- 
received  notion.  Almost  everywhere  within  the  bounding 
reef,  except  where  special  circumstances  have  favored  the  de- 
velopment of  coral  and  millepore  patches,  the  bottom  is  largely 
barren,  presenting  a  nearly  uniform  expanse  of  coral  sand. 
This  is  the  paradise  of  the  sea-urchin  (Toxopneustes  variegatus) 
and  of  the  great  black  sea-cucumber  which  is  so  common  in 
the  inner  waters.  From  the  anchorage  of  the  Villa  Frascati  we 
watched  day  after  day  the  uncouth  ebony  masses  of  the  latter, 
scattered  like  so  many  black  blotches  over  the  sand.  Only  ex- 
ceptionally could  they  be  observed  to  change  their  position, 
although  the  rolls  of  sand  drawn  over  the  surface  indicated 
that  such  changes  were  not  uncommon;  not  improbably  their 
perambulations  take  place  largely  at  night-time,  when  their 
movements  would  not  be  likely  to  attract  attention.  In  the 
normal  condition  of  rest  and  apparent  non-animality  the  creat- 
ure might  readily  pass  aggressive  observation,  even  though 
it  be  the  most  conspicuous  object  on  the  bottom  ;  and  in  thus 
deceiving  what  might  otherwise  be  formidable  enemies  it  is 
probably  largely  assisted  by  its  forbidding  black  color.  It  is 
a  significant  fact,'  although  it  may  hold  no  special  relation  in 
the  matter,  that  another  form  of  holothurian  (like  the  latter, 
new  to  science),  of  almost  equal  size,  and  with  a  ground  color 
of  reddish-yellow,  occupies  the  same  haunts,  but  in  vastly  di- 
minished numbers.  Can  it  be  that  it  is  suffering  extermina- 
tion through  the  possession  of  a  more  attractive,  even  though 
less  apparent,  coloration  ? 


GENERAL  IMPRESSIONS.  11 

Some  of  the  pleasantest  of  our  leisure  hours  in  the  Bermudas 
were  passed  in  gazing  into  the  kaleidoscopic  waters  which 
bathe  the  gardens  of  the  Villa  Frascati,  and  who  that  has  once 
glanced  into  this  liquid  glass  can  forget  the  picture  that  is  there 
presented?  A  giant  palette  dipped  beneath  the  water.  We 
have  the  same  bright  smudges  of  cardinal  and  lemon-yellow, 
the  streaks  of  green  and  blue,  the  j-urples,  oranges,  and  blacks 
— in  short,  all  that  brilliancy  and  wealth  of  color  which  belong- 
to  the  painter's  upper  row.  A  species  of  encrusting  sponge, 
possibly  a  Microscionia,  made  large  patches  of  the  brightest 
red  on  some  of  the  detached  rock,  while  immediately  alongside, 
another  sponge  formed  clumps  of  equally  brilliant  yellow,  and 
still  another,  lesser  patches  of  green.  This  violent  contrast  of 
color,  which  is  still  further  intensified  by  the  whiteness  of  the 
supporting  coral  sand,  is  kept  in  a  pure  key.  There  is  no  dis- 
cord, and  not  very  much  more  true  harmony  ;  it  is  strongly 
marked  individuality.  If  any  one  still  doubted  that  ocean 
water  had  a  natural  color  of  its  own,  a  single  glance  at  the 
flowing  emerald  would  have  been  sufficient  to  dispel  all  doubts 
in  the  matter. 

The  most  beautiful  of  the  inner  waters  of  the  archipelago 
is  Harrington  Sound,  an  almost  closed  lagoon  which  extends 
for  about  three  miles  eastward  from  Flatts  Village.  Its  only 
open  communication  with  the  sea  is  by  way  of  Platts  Inlet,  the 
extreme  contraction  of  which  compels  the  water  to  flow  in  and 
out  with  the  fury  of  a  mill-race.  We  did  much  of  our  dredg- 
ing here,  but  scarcely  met  with  that  success  which  we  had 
anticipated.  The  bottom  is  manifestly  largely  a  sand-barren, 
and  in  a  general  sense  unproductive.  We,  however,  picked  up 
specimens  of  a  beautiful  new  species  of  Chromodoris,  and 
quantities  of  a  remarkably  crussiform  Chaina.  The  latter 
more  nearly  approaches  a  fossil  from  the  Pliocene  deposits  of 
Florida  than  any  other  species  with  which  I  am  acquainted. 
Along  the  borders  of  the  Sound  the  coral-growth,  consisting 
mainly  of  Isophyllia,  Oculina  and  SiderastraBa,  is  largely 
developed,  but  we  everywhere  failed  to  detect  traces  of  the 


12  THE  BERMUDA  ISLANDS. 

large  meandrinseform  types  which  form  such  a  prominent 
feature  in  the  life  of  Castle  Harhor.  In  the  latter,  again,  the 
Isophyllias  were  largely  wanting.  Probably  upon  the  much 
greater  depth  of  water  in  Harrington  Sound,  and  the  absence 
of  a  submarine  platform,  is  dependent  mainly  the  difference 
in  the  coral  life  of  the  two  almost  contiguous  bodies  of  water. 

It  is  difficult  to  conceive  of  a  more  beautiful  and  refreshing 
sight  than  that  which  is  presented  by  the  sheltered  coral  pools, 
with  their  wealth  of  color,  which  bite  here  and  there  beneath 
the  crumbling  banks.  Corals,  millepores,  and  stone-encrusting 
Algse  vie  with  each  other  in  building  up  the  common  domain, 
whose  most  intricate  details  are  revealed  by  the  transparency 
of  the  waters.  Even  the  tiny  polyps  may  be  seen  expanding 
their  delicate  crowns  of  tentacles.  What  a  charming  vision  of 
the  busy  life  about  us!  The  sea-anemones  are  especially 
abundant  in  these  rock-shelters,  and  some  of  them  are  strik- 
ingly beautiful;  but  on  the  whole  they  are  less  brilliantly 
colored  than  those  of  our  northern  shelters.  Among  the  corals, 
some  of  the  species  of  Isophyllia  were  the  most  highly  colored, 
the  browns  and  greens  being  remarkably  rich.  Below  a  depth 
of  a  comparatively  few  feet  coral-life  largely  disappeared,  and 
along  the  actual  floor  of  the  Sound,  say  at  depths  of  from  six 
to  eight  fathoms,  we  only  obtained  Oculina.  No  haul  of  over 
ten  fathoms  ever  brought  up  a  coral. 

During  much  of  our  stay  on  the  Sound  the  water  was  very 
rough,  and  its  inroads  upon  the  bordering  cliffs  and  crags  were 
painfully  manifest.  The  Sound  is  now  actually  making,  and 
without  question  it  has  been  in  this  condition  of  self-formation 
for  a  long  time  past.  The  ledges,  islands,  and  isolated  rocks 
all  speak  of  destruction,  and  of  the  former  occupancy  of  the 
basin  by  dry  land.  At  the  present  time  the  general  depth  of 
the  Sound  may  be  taken  at  about  45  to  60  feet,  although  our 
line  frequently  sounded  12  fathoms  ;  the  greatest  measurement 
was  made  in  what  is  known  as  the  Devil's  Hole  opposite 
Peniston  Point,  where  the  line  ran  out  14  fathoms.  I  was 
informed,  however,  by  the  American  Consul,  the  late  Mr.  Allen, 


GENERAL  IMPRESSIONS.  13 

that  soundings  had  been  obtained  in  the  same  place  of  16 
fathoms.  The  dredge-net  usually  brought  up  from  these 
greater  depths  only  a  grayish-white  mud  or  ooze,  largely  made 
up  of  coral  and  coralline  fragments  and  the  debris  of  the 
crumbling  cliffs,  among  which  the  perfectly  formed  tests  of  a 
limited  number  of  Foraininfera — Globigerina,  Orbiculina — 
could  be  made  out.  A  deposit  is  manifestly  accumulating  on 
the  floor  of  the  Sound,  and  at  a  rate  evidently  much  more 
rapid  than  that  which  marks  disappearance  through  solution. 

Our  journeyings  through  the  country  were  largely  made  by 
cart,  a  ramshackle  two-wheeled  arrangement  which  we  canopied 
so  as  to  protect  us  from  the  force  of  the  sun's  rays.  That  a 
party  of  nine,  men  and  women  closely  huddled  together,  with 
an  arrangement  for  traveling  such  as  we  had,  should  have  at- 
tracted some  little  attention,  or  even  drawn  out  the  smiles  of 
the  kindly-disposed  natives,  goes  without  saying.  We  found 
it  impossible  at  the  Flatts  to  obtain  a  two-horse  conveyance  of 
any  description,  consequently  we  were  compelled  to  put  up  with 
a  simple  cart,  or  with  that  in  combination  with  another  vehicle. 
Fortunately,  the  excellent  condition  of  the  country  roads  ren- 
dered traveling  even  in  our  rude  contrivance  fairly  comfortable, 
while  the  load  was  not  over  burdensome  to  the  single  animal. 
The  statement  that  has  gained  currency  that  two-horse  con- 
veyances are  practically  unknown  in  the  Bermudas  has  noth- 
ing to  support  it. 

We  did  not  suffer  so  m-uch  from  the  glare  of  the  roads  as  we 
had  anticipated.  The  anticipatory  warnings  concerning  green - 
umbrellas  and  black-goggles  had  succeeded  in  thrusting  these 
articles  of  defense  upon  us,  but  they  were  barely  more  needed 
here  than  in  any  other  limestone  region.  Nor  did  we  find  the 
heat  of  the  sun  to  be  of  that  oppressive  quality  which  report 
made  it.  The  highest  marking  of  the  thermometer  during  our 
sojourn  (July)  was  84°  F.,  considerably  lower  than  what 
we  should  have  expected,  during  the  same  season  of  the  year, 
for  the  region  about  Philadelphia  or  New  York.  We  found 
but  little  difference  between  the  temperature  of  night  and  day — 


14  THE  BERMUDA  ISLANDS. 

some  four  or  five  degrees — and  usually  the  early  hours  of  morn- 
ing were  the  most  oppressive.  At  that  time  the  atmosphere  is 
more  settled,  and  in  a  measure  lacking  in  those  refreshing 
breezes  which  make  the  climate,  despite  the  heaviness  which 
a  moisture-laden  atmosphere  brings  with  it,  pleasantly  bearable. 
Except  in  localities  where  you  are  temporarily  debarred  from 
the  benefits  of  the  breezes,  the  heat  is  in  no  way  oppressive,  and 
on  the  open  waters  we  found  that  the  difficult  work  of  dredge- 
hauling  could  be  done  without  special  fatigue,  and  without 
drawing  perspiration.  Indeed,  this  work  was  not  nearly  as 
trying  as  I  found  it  two  years  before  in  the.  waters  of  Nantucket 
Island.  The  balmy  air  of  evening  and  the  later  hours  is  de- 
licious, and  permits  of  a  night  being  passed  in  the  open  air 
without  discomfort.  Only  from  sudden  showers  is  any  annoy- 
ance to  be  anticipated.  These,  however,  are  sometimes  very 
sudden,  and  seemingly  the  rain  falls  at  times  when  it  would 
be  least  expected.  It  was  a  common  saying  with  us  that  a 
clouded  sky  could  be  relied  upon,  whereas  the  opposite  was 
threatening.  The  passing  off  of  a  shower  is,  however,  just  as 
rapid  as  its  beginning,  and  often  the  whole  rain  was  over  in  a 
few  seconds.  Only  once  did  we  experience  a  lasting  furious 
rain,  but  then  the  water  descended  in  torrents.  But  within  an 
hour  after  the  close  even  of  this  rain  the  roads  were  practically 
dry. 


II. 


THE  NORTH  ROCK. 


In  the  open  ocean,  north  of  Flatts  Village,  lies  a  cluster  of 
rocks  upon  which  the  foot  of  man  has  thus  far  but  rarely  trod. 
Gray  and  weather-beaten,  they  are  yet  firm  as  of  old,  and  bear 
well  the  marks  that  a  struggle  with  the  sea  has  impressed  upon 
them.  During  some  six  hours  of  the  day  these  isolated  rock 
pinnacles,  of  which  the  largest  barely  exceeds  the  double- 
height  of  man,  are  united  to  one  another  by  a  species  of  or- 
ganic or  living  basement,  while  during  the  remaining  hours 
they  are  immersed  in  the  blue  coralline  sea  by  which  they  are 
everywhere  surrounded.  Nine  miles  distant  lies  Bermuda — 
or  more  properly,  the  hundred  or  more  islands  and  islets  which 
together  constitute  the  Bermudas — a  soft  line  of  purple 
stretched  against  the  southern  sky.  To  the  southwest  the  eye 
detects  the  white  shaft  of  Gibb's  Hill  Light,  a  giant  pillar  cap- 
ping one  of  Bermuda's  greatest  elevations — 245  feet — while  to 
the  southeast  the  pharos  of  St.  David's,  the  all-guardian  of  the 
archipelago,  plays  hide-and-seek  with  the  foot-hills  that  nestle 
at  its  base.  Beyond  is  all  sea — the  green-blue  ocean  in  whose 
bosom  are  locked  the  treasures  of  an  unseen  world. 

This  fragment  of  a  universe  is  practically  all  that  is  to  be 
seen  of  the  great  outer  reef,  which  lies  buried,  even  at  low 
water,  at  some  little  depth  beneath  the  surface.  The  distance 
from  the  main-land  renders  access  to  it  difficult,  and  it  is  only 
under  exceptionally  favorable  conditions  of  water  that  it  can 
be  approached  with  advantage.  Even  after  the  surrounding 
shallows  have  been  crossed  it  is  not  yet  easy  to  effect  a  landing, 


10  THE  BERMUDA  ISLANDS. 

and  we  found  that  our  pilot  was  little  inclined  to  risk  his  boat 
in  the  ragged  growth  of  millepore  and  serpula  which  every- 
where forms  the  superficial  portion  of  the  growing  reef.  This 
inaccessibility,  doubtless,  accounts  for  the  fact  that  so  few 
among  the  visitors  to  these  distant  shores — or  for  that  matter, 
even  residents — have  visited  this  remarkable  spot,  which  is,  be- 
yond comparison,  the  most  interesting  feature  which  the  Ber- 
mudas have  to  offer.  To  those  who  have  seen  the  reef  merely 
by -sailing  over  it,  it  can  be  well  said  that  they  have  but  half 
seen  it — they  have  missed  its  greatest  charms. 

The  traverse  of  the  inner  waters  between  Flatts  Village 
and  the  reef  is  of  itself  replete  with  interest.  Here  and  there 
glimpses  of  the  bottom  reveal  wonders  of  a  natural  fairy-land 
which  bid  welcome  to  a  realm  of  indescribable  beauty.  Corals 
of  bright  orange  and  yellow,  sponges  of  black  and  cardinal, 
nodding  sea-fans  of  purple  and  silver,  and  fishes  of  all  that 
brilliancy  of  coloring  which  distinguishes  the  ichthyic  element 
of  the  coralline  seas,  these  and  much  more  are  the  pictures 
that  appeal  invitingly  to  a  habitation  in  the  oceanic  waste. 
The  ruffled  surface  of  the  water  bars  out  that  clear  vision 
to  which  we  are  accustomed  in  our  meadow-wanderings,  but 
the  magic  of  a  few  drops  of  oil,  or  the  stilling  of  the  water- 
glass,  brings  out  the  relief  in  the  most  wondrous  detail.  The 
bottom  bristles  with  a  forest  of  rising  stems  and  branches,  the 
work  principally  of  that  most  indefatigable  hydroid-coral,  the 
millepore,  and  through  it  are  scattered  the  roses  of  the  deep. 
Countless  black  sea-urchins  (Diadema)  lie  quietly  nestled  in  the 
maze,  while  here  and  there,  where  the  animal  shrubbery  has 
permitted  the  white  sand  to  come  to  view,  we  catch  passing 
glimpses  of  the  lonely  black  sea-cucumber  (Stichopus  diaboli), 
quiet  and  motionless,  as  in  the  stiller  waters  of  the  Sound. 
One  of  the  most  beautiful  objects  of  these  waters  is  the  pink 
tunicate  Diazona  whose  long  stems  we  hooked  up  in  association 
with  one  or  more  forms  of  Gorgonia. 

The  water  shallows,  and  we  approach  the  boundaries  of  the 
outer  reef;  the  huge  brain-corals  (Diploria)  rise  to  within  four 


PQ 


E 


THE  OUTER  BEEF.  17 

or  five  feet  of  our  keel,  and  show  their  cerebral  convolutions 
with  the  distinctness  of  cabinet  specimens.  But  those  of  us 
who  are  accustomed  to  the  white  corals  of  museum-shelves  and 
mantels  see  nothing  of  that  description  here.  The  internal 
framework  or  skeleton  is  completely  covered  by  the  living 
animal  substance,  a  thin  film  of  organic  jelly  of  the  most  brill- 
iant orange  in  this  instance,  from  the  surface  of  which  protrude 
the  ever-busy  polyps.  To  conceive  that  these  huge  blocks 
everywhere  scattered  about,  three,  four  and  five  feet  in  diameter, 
should  be  the  silent  work  of  these  tiny  organisms !  But  how 
weak  is  the  conception  compared  with  that  which  recognizes  in 
the  architecture  of  all  the  Bermudas  principally  the  labors 
of  the  coral  animal ! 

Our  launch  is  now  fairly  within  the  reef;  we  anchor,  and 
take  to  the  whale-boat,  determined  to  storm  the  little  spot  that 
nature  had  bequeathed  to  the  ocean  wave.  We  toss  gently 
over  the  inflowing  billows,  and  at  first  it  would  seem  as  though 
our  enterprise  were  to  terminate  in  failure.  But  a  moment 
more,  and  success  is  achieved.  The  lee-side  of  one  of  the 
massive  outgrowths  of  millepore  and  serpula  permits  us  to  enter 
safely  into  our  little  port,  and,  taking  the  necessary  precautions 
to  land  where  the  solidity  of  the  marginal  growth  promised 
security  from  a 'too  sudden  plunge  into  the  sea,  we  disembark, 
critics  might  say,  in  not  very  orthodox  fashion. 

To  those  who  have  never  seen  a  growing  coral-reef  it  is 
impossible  to  describe  the  magnificence  of  the  scene.  With  rapt- 
urous delight  and  wonder  you  gaze  through  the  crystal  waters, 
and  follow  the  infinitude  of  form  and  color  that  everywhere 
surrounds  you.  The  eye  rests  but  for  a  moment  on  one  object, 
it  is  immediately  called  to  another.  Corals,  sponges,  squirts, 
lime-secreting  Algge  (nullipores)  are  welded  together  into  one 
vast  wilderness  of  coloring,  a  carpet  mosaic  of  the  most  bizarre 
pattern  and  brilliancy.  All  animal  life  is  out  in  holiday 
attire ;  the  crabs,  the  shells,  the  worms  are  painted  with  the 
same  brush  and  palette  which  were  used  in  frescoing  the  corals 
and  sponges.  Red,  green,  yellow,  and  purple  blotches  appear 


18  THE  BERMUDA  ISLANDS. 

everywhere,  and  so  finely  are  they  interwoven  that  the  outlines 
of  the  elementary  parts  lose  themselves  in  the  hody-mass  of  the 
whole.  Thus  has  nature  provided  her  weaker  offspring  with  a 
protective  coloring,  and  allowed  them  to  live  almost  unobserved 
amid  the  haunts  of  their  enemies.  We  found  the  Diadema  setosa, 
the  peer  of  all  sea-urchins,  very  abundant  on  the  reef,  where 
in  magnificent  contrast  to  the  wealth  of  color  by  which  it  was 
surrounded,  its  ebony-black  masses  stood  out  in  prominent 
relief  from  the  coral  shelters  which  it  inhabits.  All  the  individ- 
uals occupied  recesses  in  the  coral  growth,  which  they  had  by 
some  means,  probably,  managed  to  keep  open.  It  is  a  note- 
worthy fact  that  while  most  of  the  animal  forms  inhabiting 
this  portion  of  the  growing  reef  wtre  brilliantly  colored, 
harmonizing  with,  and  shielding  one  another  by,  the  party-tints 
that  had  been  culled  from  the  rainbow,  these  urchins  were 
alone  conspicuous  by  the  absence  of  any  such  protective  cloak; 
but  just  in  their  case  no  protective  guise  in  the  form  of  coloring 
is  needed,  since  these  animals  are  abundantly  able  to  shield 
themselves  by  means  of  their  greatly  attenuated  spines.  We 
found  three  other  species  of  sea-urchin,  Echinometra  subangu- 
laris,  Hipponoe  escul'enta,  and  Cidaris  tribuloides,  fairly  abundant 
in  the  coral  shelters,  the  last-named  species,  I  believe,  being 
now  for  the  first  time  recorded  from  the  islands. 

We  secured  many  specimens  of  the  large  Diadema  for  our 
collections,  but  found  that  caution  in  handling  was  necessary, 
lest  the  needle-spines  would  be  projected  into  the  flesh,  and 
there  broken  off  in  fragments.  In  what  precise  manner  the 
animal  so  deftly  manages  to  insert  its  spines  into  the  finger  tips, 
and  leave  them  there  as  reminiscences  of  its  existence  I  could 
not  determine;  but  the  fact  spoke  of  an  occult  operation  in 
painful  language.  The  urchins  are,  however,  not  the  only 
animals  that  produce  lasting  impressions  upon  the  visitor  to  the 
reefs.  The  corals  and  millepores  are  all  endowed  with  stinging 
powers,  and  the  ulcerations  and  swellings  which  their  nettle- 
cells  produce  are  frequently  retained  in  quiet  discomfort  for 
several  days.  The  jelly-fishes  and  Medusae  are  equally  dis- 


THE  OUTER  REEF.  19 

agreeable  in  their  companionship,  and  on  two  occasions  we 
found  that  long  after  stranding,  and  for  hours  after  life  had 
been  apparently  extinguished,  the  Portuguese-man-of-war  was 
still  able  to  discharge  with  effect  its  tiny  darts,  and  produce  an 
impressive  irritation. 

Of  the  larger  jelly-fishes  frequenting  the  neighborhood  of  the 
reef  we  found  the  pink  Aurelia  and  the  rhizostome  especially 
numerous,  and  it  was  interesting  to  watch  with  what  equabil- 
ity these  delicate  creatures  weathered  the  rolling  billows,  how 
nicely  they  adjusted  their  presence  so  as  to  evade  the  breaking 
water,  and  kept  their  pulsating  bells  in  the  comparatively 
quiet  zone  of  only  a  few  inches  depth  beneath  the  surface. 

The  more  tranquil  pools  of  the  reef  are  in  places  stocked 
with  fish,  which  partake  of  the  same  brilliant  mould  which 
distinguishes  the  lower  animals.  The  members  of  the  tribe  of 
labroids,  such  as  the  golden  "Spanish  lady,"  the  " blue-fish," 
and  "  hind"  were  especially  conspicuous,  darting  rapidly  from 
shelter  to  shelter  as  our  shadows  were  cast  upon  the  water. 
V/ading  through  one  of  these  pools  I  disturbed  the  peace  of  some 
thirty  or  forty  fishes  of  the  most  intense  blue  and  purple,  but 
the  rapidity  of  their  movements  rendered  a  determination  of 
the  species  impossible.  We  observed,  however,  none  of  the 
lovely  angel-fishes,  with  their  long  streamers  of  blue  and  yel- 
low, nor  any  of  the  parrot-fishes  proper,  which  apparently  find 
a  more  congenial  home  in  the  inner  waters  of  the  archipelago. 

The  surface  of  the  reef  that  is  here  exposed  above  low-water 
is  barely  more  than  a  few  yards  in  width,  and  is  everywhere 
honey-combed  into  pits  of  greater  or  less  depth.  Many  of  these 
pits  were  dry,  or  nearly  so,  while  others  are  permanently  filled 
with  water ;  but  whether  you  examine  the  one  or  the  other, 
you  find  the  same  traces  of  a  busy  animal  life.  Tiny  crabs  are 
especially  abundant,  and  they  may  be  seen  scurrying  about  in 
all  directions ;  as  elsewhere  the  hermits  have  well  provided 
themselves,  and  the  moving  domiciles  of  Purpura,  Nassa,  and 
Columbella,  with  their  colored  patches  of  algal  growth,  are  con- 
spicuous objects  on  the  floor  of  the  reef.  Seemingly  none  of  the 


20  THE  BERMUDA  ISLANDS. 

larger  or  more  conspicuous  shells  of  the  archipelago  are  found 
here,  nor  indeed,  can  it  be  said  that  shells  of  any  description 
are  numerous. 

The  predominant  form  of  coral,  at  least  in  the  upper  layer, 
is  the  Porites,  whose  masses  of  bright  orange  appear  here  and 
there  through  the  more  sombre  tints  of  the  serpula  by  which 
they  are  almost  everywhere  covered.  It  grows  to  within  a  few 
inches  of  the  water-line,  but  nowhere  did  we  see  it  protrude 
above  the  surface,  even  at  lowest  water.  This  is  true  of  all  the 
stone-corals  with  which  we  came  in  contact,  and  also  of  the 
millepore.  But  we  found  large  encrusting  patches  of  that  sin- 
gular actinioid  form,  Corticifera  flava,  completely  exposed,  and 
beyond  the  reach  of  spray.  The  length  of  exposure  is,  how- 
ever, short,  and  probably  sufficient  water  is  retained  during 
this  time  within  the  cavernous  mass  to  minister  properly  to  the 
wants  of  the  organism. 

The  serpula  grows  in  dense  bunches,  forming  a  true  base- 
ment, which  is  admirably  adapted  toward  withstanding  the  at- 
tacks of  the  sea.  Indeed,  everywhere  along  the  border  where 
the  surf  beats  hardest,  the  serpula  growth  was  most  largely  de- 
veloped, and  to  such  an  extent  as  to  form  a  raised  rim  or  bar- 
rier to  the  in  ore  protected  inner  side.  Breaking  in  on  all  sides 
the  surf  has  created  a  number  of  more  oriess  irregularly  oval 
islets  with  depressed  centers — or,  more  properly,  with  elevated 
borders — diminutive  atolls,  as  it  were ;  and,  indeed,  this  struct- 
ure has  led  naturalists  to  assume  that  the  form  of  the  true 
coral  atolls,  with  their  central  lagoon  and  bounding  outer  ring, 
may  have  been  produced  in  much  the  same  way,  and  without 
the  assistance  of  any  such  subsidence  as  was  considered  neces- 
sary for  their  formation  by  the  late  Mr.  Darwin.  I  feel  satisfied, 
however,  that  the  two  structures,  while  seemingly  alike,  have 
practically  little  or  nothing  in  common ;  in  the  one  case  the 
central  depression  is  merely  a  negative  one,  being  such  by 
reason  of'a  somewhat  more  rapid  growth  developed  only  from 
the  water-line,  or  within  the  surf;  while  in  the  other,  the 
hollow  extends  frequently  to  depths  far  beyond  the  zone  of 


THE  OUTER  REEF.  21 

coral  growth,  and  where,  consequently,  the  building  force  is 
entirely  removed  from  the  influence  of  special  conditions  exist- 
ing in  the  superficial  layers  of  the  water.  We  may  not  yet 
have  fathomed  the  true  method  of  the  formation  of  coral  islands, 
but  such  evidences  as  I  was  able  to  obtain  at  the  Bermudas 
failed  to  convince  me  of  the  erroneousness  of  the  time-honored 
theory  of  subsidence  which  was  first  formulated  by  the  illus- 
trious Darwin,  and  which  has  so  long  ministered  to  the  wants 
of  the  geologist,  and  still  more  failed  to  satisfy  me  with  the  de- 
mands of  the  younger  school  of  geologists,  who,  under  the  lead 
of  the  venerable  Duke  of  Argyll,  have  pinned  to  their  standard 
the  now  almost  classical  motto:  "Conspiracy  of  Silence." 

I  could  not  readily  determine  to  what  extent  the  ocean  side 
of  the  reef  was  more  profuse  in  its  coral  growth  than  the  in- 
ner side.  Seemingly  there  could  not  be  much  difference,  for 
the  profusion  of  the  inner  life  was  such  as  to  make  it  difficult 
to  conceive  how  it  could  have  been  measurably  exceeded. 
Probably  in  this  regard  the  Bermudas  form  an  exception  to 
the  supposed  general  rule  which  defines  a  comparatively  barren 
area  immediately  back  of  the  surf.  Surely,  we  found  nothing 
of  the  kind  here. 

I  was  also  much  impressed  by  the  fact  that  there  were  here 
no  loose  boulders  of  rock,  such  as  it  might  have  been  assumed 
would  be  thrown  up  by  the  disintegrating  force  of  the  breakers. 
Everything  was  firm  and  compact,  except  along  the  margins, 
where  the  growth  of  millepore  formed  veritable,  but  readily 
destructible,  chevaux-de-frise.  Walking  on  this  part  is  danger- 
ous, since  it  is  not  always  easy  to  determine  how  strong  the 
growth  is,  nor  how  soon  one  may  find  his  way  into  one  of  the 
numerous  water- passages  which  honeycomb  the  mass.  We  had 
experience  of  this  danger  in  wading  within  the  millepore 
shallows  of  Devonshire  Flatts.  The  absence  of  coarse  debris 
is,  doubtless,  in  a  measure,  due  to  the  small  extent  of  land 
exposed,  and  to  the  depth  of  water  which  covers  the  greater 
part  of  the  reef.  A  rise  in  the  reef  would  probaby  bring  about 
other  conditions — as  was  manifestly  the  case  formerly — but 


22  THE  BERMUDA  ISLANDS. 

even  then  the  solidity  and  compactness  of  the  growth  would 
render  the  process  of  undermining  and  disruption  a  slow  one. 
This  is  also  true  of  the  reefs  on  the  south  side  of  the  island,  the 
crests  of  which  are  serpuloid,  while  the  lee-slopes  are  fairly 
covered  with  large  Mseandrinas.  We  but  rarely  came  across  a 
loose  block  of  stone  on  the  beach,  and  where  such  was  found 
it  could  be  generally,  if  not  always,  identified  as  the  disrupted 
part  of  the  cliffs  upon  which  the  fury  of  the  surf  was  expended. 
The  examination  of  the  lime-sand  of  the  inner  waters  only 
exceptionally  showed  recognizable  coral  fragments,  although  it 
was  very  largely  composed  of  the  debris  of  the  more  friable 
millepore.  Indeed,  it  might  be  said  that  the  sand  is  properly 
a  shell  and  millepore  sand,  rather  than  one  of  coral  formation, 
and  this  is  also  true  in  a  measure  of  the  cliff-sand  of  the  main 
body  of  the  islands. 

We  passed  the  better  part  of  three  hours  on  the  reef,  but  by 
the  end  of  this  time  the  water  was  gaining  upon  the  spot 
rapidly.  In  a  few  short  hours  the  reef  would  again  be  entirely 
covered,  save  the  three  gray  pinnacles  which  constitute  the  lone 
North  Rock. 


III. 


THE   PHYSICAL   HISTORY  AND  GEOLOGY   OF  THE 
BERMUDA  ISLANDS. 


The  reefs,  islands,  and  lagoons  which  together  constitute 
the  Somers  Archipelago  cover  an  elliptical  area,  bearing 
somewhat  east  of  northeast,  of  about  220  square  miles, 
of  which  by  far  the  greater  part  is  occupied  by  water.  The 
land  portion  is  confined  almost  wholly  to  the  south  and 
southeast,  where  it  makes  a  broken  irregular  crescent,  some 
fifteen  miles  in  length,  and  from  one  to  three  miles  in 
width.  Five  principal  islands,  of  which  the  largest,  with 
nearly  10,000  acres,  contains  approximately  three-quarters  of 
the  entire  land  surface  exposed  within  the  archipelago,  are  the 
components  of  this  crescent,  about  which  are  scattered  some 
two  hundred  or  more  islets  and  isolated  rock-pinnacles.  The 
great  body  of  water  or  lagoon,  as  it  is  sometimes  called,  which 
lies  north  of  this  chain  of  islands,  and  is  in  direct  communica- 
tion with  the  open  sea,  is  in  a  measure  delimited  by  the  ellipse 
of  the  outer  reef,  which  is  wholly  submerged  even  at  low  water, 
except  at  two  or  three  points,  the  most  conspicuous  of  which  is 
at  the  North  Rock. 

The  depth  of  water  in  this  outer  lagoon  is,  in  general, 
about  40-50  feet,  although,  exceptionally,  our  sounding-line 
dropped  to  10  or  11  fathoms.  For  some  little  distance 
before  the  outer  reef  is  reached  the  water  shallows  to  20-30 
feet,  and  at  various  spots  within  the  open,  serpula  and  mille- 
pore  growths  rise  to  within  a  foot  or  so  of  the  surface,  or 
even  completely  up  to  it,  forming  irregular  oval  patches, 
which  can  be  distinguished  even  at  a  distance  by  the  discolor- 
ation of  the  waters. 


24  THE  BERMUDA  ISLANDS. 

An  open  continuation  of  this  outer  water  is  the  Great 
Sound,  which  is  to  an  extent  land-locked  by  the  "  hook " 
of  Main  Island,  and  its  disrupted  continuation,  Somerset 
and  Ireland  Islands.  At  the  eastern  end  of  the  archipelago 
an  incursion  of  the  southern  waters  has  formed,  or  helped  to 
form,  the  lagoon  known  as  Castle  Harbor,  an  extensive 
body  of  water,  with  a  depth  of  from  30  to  40  feet,  whose 
oceanic  boundaries  are  well  seen  in  Cooper's,  Castle  and 
Nonsuch  Islands,  and  their  dissociated  fragments.  Castle 
Harbor  stands  also  in  direct  communication  with  the  northern 
waters  by  means  of  one  or  more  channels,  known  as  "  The 
Reaches,"  which  are  in  part  largely  silted  and  coral-grown,  and 
consequently  difficult  of  passage. 

Harrington  Sound,  which  bites  into  the  Main  Island  alone, 
is  the  most  nearly  land-locked  of  the  inner  waters,  and  at  the 
same  time  the  deepest  water  in  the  archipelago.  The  average 
depth  is  probably  not  less  than  nine  or  ten  fathoms,  and  our 
line  frequently  dropped  to  12  fathoms.  We  sounded  14 
fathoms  in  the  southern  bay  opposite  the  Devil's  Hole,  and  I 
was  informed  that  16  fathoms  had  been  obtained  in  the  same 
locality.  Although  two  miles  in  length,  and  approximately 
a  mile  and  a  half  in  greatest  width,  this  extensive  body  of 
water  communicates  with  the  outer  sea  by  a  channel  not  more 
than  50  feet  in  width,  the  Flatts  Inlet.  The  breaking  action 
of  the  waters,  the  undermined  ledges,  and  the  vertical  cliffs  all 
clearly  indicate  that  the  Sound  is  still  expanding,  and  it  is 
merely  a  question  of  time,  if  the  present  conditions  continue, 
when  it  will  be  more  in  the  nature  of  an  open  bay  than  of  a 
land-locked  lagoon. 

The  reefs  on  the  south  side  of  the  archipelago  approach  in 
places  to  within  a  hundred  yards  or  as  many  feet — or  even  less — 
of  the  chain  of  islands,  from  which  they  are  separated  by  a 
belt  of  water  of  no  inconsiderable  depth,  and  always  existent. 
They  are,  therefore,  more  nearly  in  the  nature  of  "  barrier  " 
than  of  "  fringing  "  reefs,  if,  indeed,  they  can  be  said  to  strictly 
belong  to  either  one  of  these  two  divisions.  Opposite  the  open 


PHYSICAL  HISTORY  AND  GEOLOGY.  25 

way  communicating  with  Castle  Harbor  we  sounded  nine 
fathoms  in  the  water  back  of  the  reef,  and  I  believe  that 
this  depth,  or  even  a  considerably  greater  one,  must  be  found 
in  many  places.  On  the  outer  side  the  depth  of  water  increases 
more  rapidly,  but  not  in  a  degree  as  to  indicate  abrupt- 
ness of  descent.  The  organic  growth,  which  is  serpuloid  super- 
ficially, comes  to  the  surface  in  discontinuous  patches,  over 
whose  line  a  white  surf  may  be  seen  breaking  during  the 
greater  part  of  the  day.  These  are  the  "  boilers,"  or  secondary 
atolls,  as  they  have  been  sometimes  called. 

The  outer  soundings  made  by  the  officers  of  the  "  Challenger" 
indicate  a  gradual  descent  of  the  bottom  for  a  distance  of 
about  a  mile,  when  a  much  more  abrupt  slope  begins.  It  is 
claimed  that  within  the  first  belt  the  average  depth  does  not 
exceed  12  fathoms,  but  we  sounded  13  fathoms,  after  making 
full  allowance  for  slip,  at  a  distance  of  not  more  than  300  feet 
from  the  breaking  surf.  Our  facilities,  however,  did*  not  per- 
mit us  to  make  extended  observations  in  this  direction,  nor 
was  the  condition  of  the  water,  when  we  crossed  over  the  reef, 
favorable  for  such  observations.  At  a  point  seven  miles  from 
the  northern  reef  the  "  Challenger"  obtained  the  extraordinary 
depth  of  12,000  feet,  which  would  give  an  average  descent  of 
slope  of  one  in  three,  exceeding  probably  that  of  any  equal 
slope  on  the  land  surface.  Drained  of  its  surrounding  waters, 
the  Bermudas  would,  from  this  side,  appear  like  a  stupendous 
tower,  in  comparison  with  which  the  principal  mountain 
peaks  of  the  land  would,  as  far  as  abruptness  of  slope  is  con- 
cerned, sink  into  insignificance.  Yet  it  would  seem  that,  in  a 
general  way,  at  a  distance  of  ten  miles  in  nearly  all  directions 
the  depth  is  only  from  9,000  to  13,000  feet,  or  not  more  than 
that  which  is  found  at  an  equal  distance  off  the  sub-continental 
plateau.  Twenty  miles  to  the  south  west-by-west  of  the  Ber- 
mudas two  submerged  banks  come  to  within  20-50  fathoms  of 
the  surface,  and  seemingly  represent  the  continuation  of  a 
range  of  heights  of  which  the  Bermudas  constitute  a  section. 
But  not  impossibly  they  are  merely  the  summits  of  isolated 


26  THE  BERMUDA  ISLANDS. 

volcanoes,  such  as  the  Bermudas  may  themselves  be;  the  dis- 
tance between  the  two  groups  is  amply  sufficient  to  allow  of 
both  of  them  to  slope  gradually  and  independently  to  their 
bases  without  necessitating  the  assumption  of  a  connecting 
backbone  or  ridge.  The  great  depth  of  water,  moreover,  which 
lies  at  no  great  distance  to  the  west,  and  likewise  in  the  east, 
would  seem  to  offer  no  support  to  the  notion  of  such  a  sub- 
merged ridge,  which  would  necessarily  have  to  be  of  limited 
extent.  Still,  the  shortness  of  the  line  cannot  be  looked  upon 
as  strictly  negative  evidence,  since  abbreviated  chains  with 
lofty  summits  are  not  absolutely  unknown,  even  if  they  are 
of  exceptional  occurrence. 

The  main  islands  of  the  archipelago  present  approximately 
identical  features.  Gently  undulating  hills,  rising  sometimes 
with  the  symmetry  of  sugar-cones,  alternate  with  broadly  open 
lowland,  and  pleasantly  diversify  the  landscape.  Along  much 
of  the  northern  shores  these  elevations  gracefully  descend  to 
the  water-line,  where  they  form  long  reaches  of  sand-beach, 
or  terminate  in  abrupt  escarpments,  largely  undercut,  and 
usually  of  inconsiderable  height.  Viewed  from  an  eminence, 
this  succession. of  undulating  hills  and  dales,  or  perhaps  more 
properly  stated, "  ups  and  downs,"  with  their  inclosed  lagoons, 
projecting  promontories,  and  scattered  islands  and  islets,  forms 
a  most  captivating  picture,  whose  beauty  is  further  enhanced 
by  the  magnificent  contrasts  of  color  that  are  presented.  To 
the  geologist  the  picture  immediately  suggests  a  region  of  sub- 
mergence, or  such  as  would  be  formed  were  the  more  interior 
districts  of  Main  Island  suddenly  depressed  beneath  the  water. 

At  certain  spots,  well  shown  on  the  northern  and  southern 
shores  of  Harrington  Sound,  and  on  the  Walsingham  tract  of 
Castle  Harbor,  the  water  has  cut  vertical  faces  from  the  hill- 
slopes,  and  constructed  cliffs  of  majestic  and  picturesque  ap- 
pearance. The  Abbott's  Cliffs  of  Harrington  Sound  have  an 
altitude  of  probably  not  less  than  50  or  60  feet.  Along  the 
south  shore  a  long  line  of  almost  continuous  and  imposing 
cliffs  faces  the  ocean.  These  receive  the  full  force  of  the  battling 


PHYSICAL  HISTORY  AND  GEOLOGY.  27 

waters,  and  are  cut  and  moulded  into  ragged  masses  wholly 
unlike  anything  that  is  to  be  found  on  the  opposite  shore. 
This  picture  of  wild  magnificence — the  beetling  cliffs  and  dash- 
ing spray — is  a  surprise  to  the  stranger  who  has  conceived  of 
the  Bermudas  only  from  the  north,  and  wanders  over  to  this 
side  expecting  to  see  the  picture  with  which  he  is  familiar  re- 
peated. Long  before  the  shore  is  reached  the  character  of  the 
work  that  is  here  being  accomplished  can  be  judged  of  from  the 
continuous  booming  that  falls  upon  the  ear.  Deep  bays,  alter- 
nating with  bold  and  ragged  promontories,  bite  through  the 
cliffs  in  some  places,  while  at  others  they  are  still  in  course  of 
formation.  Just  west  of  Hungary  Bay  and  at  the  Chequer 
Board,  perhaps  the  grandest  views  of  destruction  are  presented, 
but  almost  everywhere  the  picture  unfolds  itself  in  much  the 
same  detail.  We  could,  however,  form  no  true  conception  of 
the  destructive  power  of  the  sea  from  the  condition  of  the  water 
at  the  time  of  our  visit  to  the  islands.  In  the  season  of  storms, 
and  more  particularly  during  a  hurricane,  the  fury  of  the  waters 
must  be  almost  irresistible,  if  we  give  full  credence  to  the 
reports  of  experiences  of  the  inhabitants  ;  and  the  landmarks 
that  the  sea  has  impressed  upon  the  country  leave  no  room  for 
doubt  as  to  the  authenticity  of  these  reports.  The  natural 
arches  at  Tucker's  Town,  which  are  now  not  even  reached  by 
the  sea,  bear  ample  testimony  to  an  extent  of  erosion  which  is 
not  permitted  to  the  sea  in  its  ordinary  condition ;  and  the 
same  is  true  of  the  massive  cliffs,  some  80-90  feet,  or  more,  in 
height,  which  constitute  the  "  amphitheatre  "  a  short  distance 
beyond  the  arches.  Several  considerations  preclude  the  prob- 
ability of  these  structures  having  been  formed  at  a  time  when 
the  relations  of  the  land  and  water  were  different  from  what 
they  are  now,  or  that  changes  of  level  have  taken  place  since 
their  formation.  The  evidences  of  recent  encroaches  of  the  sea 
at  these  points  are  clearly  visible,  while  there  seems  to  be  noth- 
ing to  indicate  a  late  rise  of  the  land-surface.  Still,  I  must 
admit  that  the  observable  facts  at  our  command  were  not  suf- 
ficient to  warrant  us  in  assuming  positively  that  there  was  no 


28  THE  BERMUDA  ISLANDS. 

such  elevation ;  but  the  reverse  could  just  as  well  have  been, 
and  more  likely  was,  the  case. 

The  loftiest  eminence  in  all  the  Bermudas  is  Sear's  Hill, 
about  a  half  mile  southeast  of  Flatts  Village,  which  attains  the 
modest  height  of  260  feet.  We  verified  barometrically  the 
earlier  determination  of  this  height.  After  Sear's  Hill,  the 
highest  point  is  reached  in  Gibb's  Hill,  245  feet.  There  are  no 
ponds,  springs,  nor  flowing-bodies  of  freshwater  throughout 
the  archipelago,  although  at  one  or  two  points  the  water  of 
interior  collecting  pools  is  only  feebly  brackish.  Tn  a  cattle 
cistern  or  spring,  near  Peniston  Pond,  there  was  little  or  no 
salinity  appreciable,  although  the  water  did  not  appeal  invit- 
ingly to  the  human  gustatory  sense.  The  porosity  of  the  rock 
almost  immediately  absorbs  all  falling  water,  and  likewise  con- 
ducts the  sea-water  into  the  innermost  parts  of  the  islands, 
where  it  doubtless  forms  a  clearly  defined  basal  zone.  Much  of 
it  must  be  drawn  by  capillarity  above  sea-level.  All  attempts 
to  obtain  freshwater  by  means  of  artesian  borings  have  resulted 
in  failure,  by  reason  of  the  complete  permeation  of  the  oceanic 
waters.  The  large  interior  ponds  or  lakes,  all  of  which  occupy 
low  levels,  are  necessarily  brackish,  and  they  support  a  fauna 
distinctive  of  brackish  or  salt  waters.  A  fairly  large  peat-bog  oc- 
cupies the  center  of  Main  Island,  and  apparently  marks  the 
site  of  an  ancient,  now  wholly  desiccated,  lagoon.  The  peat  is 
said  to  extend  down  to  a  depth  of  40  or  50  feet*  below  the  sea- 
level,  or  to  about  the  level  of  the  floor  of  the  great  outer  water 
which  is  inclosed  by  the  northern  reef. 

The  rock  of  the  islands  is  a  granular  limestone,  which  is  in 
most  places  still  sufficiently  soft  to  permit  of  being  cut  by 
a  hand-saw.  On  exposure  to  rain  it  hardens  through  cementa- 
tion, or  deposition  of  interstitial  lime,  and  may  then  be  con- 
verted into  a  tough  and  very  resisting  material,  which  is  ad- 
vantageously used  in  the  construction  of  houses.  Piles  of 
hand-sawn  blocks  awaiting  induration  are  a  not  uncom- 

*Rice :  Geology  of  Bermuda,  Bull.  U.  S.  National  Museum,  No.  25,  p,  7.     On 
the  authority  of  General  Lefroy. 


PHYSICAL  HISTORY  AND  GEOLOGY.  29 

mon  sight  along  the  roadsides.  The  process  of  the  binding 
together  of  the  loose  particles  of  debris  which  are  to  constitute 
a  rock  is  sometimes  a  very  rapid  one,  especially  along  the 
water's  edge,  and  may  be  followed  in  its  different  stages. 

The  basal  rock  of  the  cliffs,  especially  on  the  south  shore,  is 
in  places  excessively  indurated,  and  about  as  resisting  as  a 
non-siliceous  limestone  can  well  be;  when  struck  with  a  ham- 
mer it  at  times  rings  with  all  the  intensity  of  the  volcanic  ring- 
ing rocks,  and  chips  off  as  sharp-edged  flakes.  The  granular 
structure  which  is  so  prominent  in  the  softer  rock  may  be  re- 
tained, but  it  sometimes  largely  or  wholly  disappears,  and 
the  mass  appears  to  be  homogeneously  compact.  The  matter 
of  hardness  or  compactness  is.  however,  not  one  necessarily 
depending  upon  age,  since  we  often  find  the  tougher  rock  oc- 
cupying the  high  level,  and  overlying  the  softer  rock  below. 
At  other  places  the  two  kinds  of  rock  alternate  with  one 
another.  From  the  constancy  of  its  occurrence  at,  or  near, 
the  base  of  the  island,  the  hard  subcrystalline  limestone  is 
locally  known  as  the  "base  rock ; "  it  serves  largely,  but  by  no 
means  invariably,  to  distinguish  the  old  beach  formation,  and 
thus  to  locate  the  former  sea-border.  The  same  rock  forms 
the  lower  moiety  of  the  three  pinnacles  of  the  North  Rock. 

The  constituent  particles  of  the  softer  limestone  are  of  about 
the  size  of  a  pin's  head,  or  smaller,  among  which  the  debris 
of  shells  and  millepores  are  distinctly  recognizable.  Coral 
fragments  are  apparently  much  less  abundant,  and,  indeed, 
it  was  only  with  difficulty  that  I  determined  these  at  all, 
except  where,  at  long  intervals,  fragments  of  large  size  were 
caught  up  in  the  mass.  Possibly,  the  finer  undefined  particles 
may  have  been  those  of  corals,  whose  cellular  structure  would 
have  readily  lent  itself  to  a  powdering  such  as  would  com- 
pletely efface  determining  characters.  Still,  the  fact  remains 
that  much,  or  most,  of  this  rock  is  made  of  millepore  and  shell 
fragments,  and  whatever  part  corals  may  have  taken  in  its 
formation,  it  cannot  be  considered  to  be  a  simple  coral  rock. 
The  examination  of  the  long  stretch  of  beach  which  faces  the 


30  THE  BERMUDA  ISLANDS. 

north  side  of  St.  George's  Causeway  also  failed  to  show  much 
evidence  of  coral  growth,  although  shells  and  millepore  frag- 
ments were  packed  in  endless  quantities;  the  tests,  perfect  and 
imperfect,  of  the  foraminifer  genus  Orbiculina  were  also  very 
ahundant.  I  do  not  wish  to  be  understood  as  saying  that  the 
islands  are  not  really  of  coral  formation ;  that  a  coral  funda- 
ment exists,  needs  no  further  demonstration  than  is  furnished 
by  the  rich  growth  of  Diploria  and  Mseaiidrina  within  the 
reef- waters,  and  by  the  coral  fragments  and  masses  that  are 
inclosed  by  the  beach  formation.  I  wish  merely  to  emphasize 
the  important  part  which  organisms  other  than  corals  have 
taken  toward  the  shaping  and  the  making  of  the  rocks, 
especially  of  the  superficial  parts  which  have  lent  themselves 
to  wind-action. 

The  true  relations  of  the  Bertnudian  rock  were  first  clearly 
established  by  Nelson.*  With  remarkable  sagacity  this  ob- 
server read  the  history  of  the  discordant  layers,  here  horizon- 
tal, there  steeply  inclined,  now  arched  in  one  direction,  then 
in  another,  which  appear  in  all  the  sections,  and  he  was  not 
slow  to  point  out  that  they  were  the  result  of  wind-drift — mere 
shifting  (calcareous)  sands  which  had  been  thrown  about 
promiscuously  by  the  winds,  and  had  solidified  in  layers  in 
the  positions  where  they  had  been  finally  dropped.  This  in- 
terpretation stands  to-day  as  firmly  established  as  it  stood 
when  it  was  first  enunciated  upwards  of  a  half  century  ago. 
The  thin  knife-sheets  which  are  so  characteristic  of  this  drift- 
rock  build  up  massive  beds,  which  are  thrown  together  in 
most  irregular  confusion — dove-tailed,  apparently  faulted, 
lenticulated,  and  otherwise.  No  more  interesting  exposures  can 
be  had  than  the  faces  of  the  road-walls,  both  in  the  city  and  in 
the  country,  where  synclines,  anticlines,  slopes,  and  horizontals 
appear  sometimes  in  the  space  of  a  few  yards.  At  other  places 
no  bedding,  beyond  the  thin  lamination,  is  apparent,  and  the 
whole  mass  rests  concordantly  either  in  straight  or  undulating 
lines. 

*Trans.  Geol.  Soc.  of  London,  2d  Ser.,  vol.  v,  Part  I,  pp.  103-123. 


PHYSICAL  HISTORY  AND  GEOLOGY.  31 

The  first  process  toward  the  forming  of  this  rock  must  neces- 
sarily be  the  pounding  up  of  the  material  out  of  which  it  is  con- 
structed. Wherever  the  polyps  build  close  to  the  surface  their 
habitations  are  attacked  by  the  surf  which  they  themselves 
create.  The  long  white  line  of  foam  which  meets  the  eye  of 
the  observer  gazing  southward  from  any  eminence,  and  parts  the 
blue  waters  of  the  outer  world  from  the  more  nearly  green 
within,  is  but  the  line  of  battle  between  the  organic  arid  the 
inorganic  forces.  It  is  here  that  life  asserts  her  supremacy 
over  the  sea,  and  it  is  here  that  the  sea  maintains  her  right  of 
domain  as  an  inheritance  of  prior  birth.  Blocks  of  coral  and 
coralline  are  detached  and  broken,  their  parts  are  rocked  to  and 
fro  in  the  withering  crest,  and  ultimately,  when  the  fragments 
have  been  sufficiently  punished  by  the  sea,  they  are  handed 
over  for  further  chastisement  to  the  action  of  the  wind.  In 
this  way  the  particles  are  ground  finer  and  finer,  a  true  sand 
is  formed,  and  dunes  begin  to  rear  their  heads  above  the  ocean 
level.  Traveling  in  the  line  of  the  wind  the  dunes  pass  on- 
ward, climb  over  one  another's  backs,  and  comb  the  gently 
flowing  crests ;  from  pigmy  hillocks  they  rise  into  well-fashioned 
knolls,  and  ultimately  stand  as  the  eminences  which  to-day  are 
the  Bermudas.  No  one  who,  on  the  south  shore,  has  watched 
the  great  tongues  of  moving  sand, — the  sand  glaciers  of  Tucker's 
Town  and  Elbow  Bay,  for  example — stealthily  encroaching 
upon  the  hill-tops  of  the  interior,  and  burying  everything,  in 
the  manner  of  the  locusts  of  South  Africa,  beneath  their  man- 
tle of  destruction,  can  have  failed  to  be  impressed  by  the  char- 
acter and  the  magnitude  of  the  work  that  is  being  accomplished. 
It  is  truly  but  the  music  of  the  sea  and  wind,  but  there  is 
enough  of  it  to  turn  water  into  land.  It  seems,  indeed,  as 
though  Virgil  had  divined  some  such  region  as  this  when  he  de- 
picted the  home  of  ^Eolus  in  the  following  beautiful  lines:— 

Here  JEolus,  in  cavern  vast, 

With  bolt  and  barrier  fetters  fast 

Rebellious  storm  and  howling  blast. 

They  with  the  rock's  reverberant  roar 


32  THE  BERMUDA  ISLANDS. 

Chafe  blustering  round  their  prison  door  : 
He,  throned  on  high,  the  sceptre  sways, 
Controls  their  moods,  their  wrath  allays. 
Break  but  that  sceptre,  sea  and  land, 
And  Heaven's  etherial  deep, 
Before  them  they  would  whirl  like  sand, 
And  through  the  void  air  sweep. 

(Conington's 

The  seolian  or  wind-drift  character  of  the  Bermuda  Islands 
is  everywhere  apparent;  along  the  roads,  on  the  hillsides,  and 
in  the  caves  we  find  the  same  rock  made  up  of  organic  par- 
ticles. The  layers  or  seams,  inclining  now  one  way,  now  in 
another,  point  to  the  different  positions  into  which  the  sand 
had  been  fortuitously  cast  by  the  winds,  patted  down,  and 
built  up  into  a  series  of  superimposed  layers.  Shells,  both 
marine  and  terrestrial,  have  been  caught  up  in  the  drifts,  for 
we  find  them  now  embedded  in  the  rock,  and  scattered  over  the 
most  remote  corners  of  the  island  group.  I  picked  up  a  fairly 
large  fragment  of  coral  at  an  elevation  of  probably  not 
less  than  150  feet;  and,  doubtless,  other  equally  large  fragments 
occur  at  still  greater  heights.  In  regions  where  freshwater 
streams  abound,  the  materials  of  terrestrial  destruction  are 
washed  into  these  streams,  and  by  them  carried'  into  the  sea ; 
geologists  have  long  since  recognized  the  force  of  the  say- 
ing :  "  the  land-surface  is  on  one  grand  march  to  the  sea." 
But  here,  where  freshwater  streams  are  entirely  wanting,  and 
the  falling  drops  are  immediately  absorbed  into  the  porous 
soil,  the  conditions  are  at  least  in  one  sense  reversed — the 
march  is  in  a  direction  away  from  the  sea.  Whither  it  may 
ultimately  tend  cannot  be  foretold. 

It  is  difficult  to  conceive  that  these  lovely  hills,  buried  beneath 
their  sombre  covering  of  juniper  and  sage  (Lantana),  should 
have  been  thus  shaped  by  the  wind ;  but  the  facts  are  plain  in 
their  statement,  and  leave  no  loop-hole  for  the  doubting 
mind.  The  height  of  the  sand-hills,  or  dunes,  for  such  they 
really  are,  is  unusually  great  for  a  coral  island,  and  serves  to 


ROYAL  PALMS;    PEMBROKE   HALL. 


PHYSICAL  HISTORY  AND  GEOLOGY.  33 

distinguish  the  Bermudas  from  other  islands  having  an  ap- 
parently related  structure.  I  fully  concur  in  the  suggestion 
thrown  out  by  Prof.  Rice  that  these  accumulations  could  only 
have  been  formed  at  a  time  when  large  areas  of  reef,  and  not 
a  simple  atoll-ring,  were  exposed  above  water-level.  At 
the  present  day  nearly  all  the  sand  is  formed  through  the  de- 
struction of  the  existing  land-mass,  and  not  as  a  product  of 
disintegration  derived  from  the  growing  reef. 

Prof.  Rice,  in  his  interesting  observations  on  the  geology  of 
Bermuda  (loc.  cit.,pp.  10-13),  correctly  distinguishes  a  "  beach  " 
rock  as  underlying  in  many  places  the  drift  rock  of  the  shores. 
He  instances  as  examples  of  such  rock  the  fossiliferous  stratum 
which  appears  in  the  chain  of  islands  stretching  across  Hamil- 
ton Harbor,  the  conglomerate  of  Stock's  Point,  near  St. 
George's,  which  rises  some  twelve  feet  above  the  water,  the 
lower  bed  of  Devonshire  Bay,  and  much  of  the  basal,  nearly 
horizontal,  strata  which  appear  on  the  south  shore.  As  char- 
acteristic of  this  beach  rock,  it  is  said  that  the  beds  nearly  uni- 
formly dip  seaward,  but  at  a  very  moderate  angle,  and  that 
they  contain  largely  of  the  remains  of  marine  animals  (corals 
and  shells).  The  rock  is  in  most  cases  very  tough  and  hard, 
and  is  largely  the  correspondent  of  the  base-rock  that  has 
already  been  described. 

We  also  found  this  beach-rock  well  developed  at  many 
points  along  the  south  shore,  where  it  rises  some  5-8  feet,  or 
exceptionally  more,  above  the  sea-level.  The  series  of  nearly 
horizontal  ledges,  sharply  defined  by  their  position  from  the 
highly  inclined  layers  of  drift-rock  by  which  they  are  sur- 
mounted, or  into  which  they  graduate  landward,  which  appear 
basally  at  the  Chequer  Board  and  at  Harris's  Bay  well  illus- 
trate the  characteristics  of  the  rock.  I  failed  however,  to  de- 
tect the  uniform  seaward  slope  of  this  rock  which  Prof.  Rice 
indicates,  nor  could  I  satisfy  myself  that  the  presence  of 
marine  organic  remains  in  a  rock  were  conclusive  for  consider- 
ing the  rock  to  be  of  beach  formation,  unless,  indeed,  such  re- 
mains were  abundant,  or  else  showed  by  their  positions  that 


34  THE  BERMUDA  ISLANDS. 

they  could  only  have  been  placed  there  through  the  normal 
manner  of  oceanic  deposition.  It  is  true  that  in  by  far  the 
greater  number  of  cases  the  rock  that  can  be  identified  as  of 
beach  formation  contains,  when  remains  are  present  at  all, 
only  the  relicts  of  marine  organisms,  and  that  the  drift-rock 
above  or  back  of  it  contains  only  the  parts  of  land  mollusks. 
But  Prof.  Rice  justly  remarks  that  the  remains  of  land  organ- 
isms can  be  readily  washed  or  drifted  into  the  sea,  and  there 
combined  with  the  organisms  that  are  subsequently  to  enter 
into  the  formation  of  a  beach-rock.  A  mixed  faunal  element 
would  thus  be  introduced.  But  much  the  same  kind  of  inter- 
mixture may  take  place  in  the  land-deposits  through  the 
washing  or  sweeping  on  high  of  marine  organisms,  or  their 
fragments,  especially  during  periods  of  high  storm.  Prof. 
Rice  recognizes  the  possibility  of  such  intermixture,  but  he  at- 
tributes it  all  to  the  action  of  the  wind.  It  is  claimed  that 
only  small  or  light  fragments  can  be  swept  up  by  it,  and  that 
necessarily  only  these  can  be  found,  under  ordinary  condi- 
tions., drifted  into  the  rock.  A  fragment  of  the  shell  of 
Spondylus  weighing  1.8  grammes,  a  valve  of  Charna,  in- 
crusted  with  tubes  of  serpula,  weighing  2.7  grammes,  and  a 
fragment  of  Mycedium,  weighing  8.3  grammes,  were  found 
by  that  investigator  in  the  sand-drifts  of  Tucker's  Town,  and 
these  weights  or  masses  are  given  as  values  of  the  carrying 
power  of  the  wind.  This,  it  appears  to  me,  is  doing  scant  jus- 
tice to  the  assistance  which  the  wind  receives  from  the  sea. 
Under  ordinary  conditions  the  action  of  the  sea  may  be 
confined  almost  wholly  to  the  line  of  beach,  but  it  certainly 
is  otherwise  during  storms.  At  such  times  there  can  be  no 
question  that  much  in  the  way  of  organic  remains  is  thrown 
far  within  the  domain  of  the  drift-rock.  The  hurling  of 
pebbles  and  stones  along  exposed  coast-lines  is  sufficient  evi- 
dence of  the  capabilities  in  this  direction.  We  were  given 
graphic  accounts  of  the  violence  of  the  waters  under  excep- 
tional conditions  of  storm,  and  were  shown,  in  the  house  of 
the  Misses  Peniston,  at  Peniston's,  a  position  reached  by 


PHYSICAL  HISTORY  AND  GEOLOGY.  35 

volumes  of  spray  which  we  should  have  believed  impossible, 
were  it  not  for  the  absolute  reliability  of  the  residents  of  the 
house  who  volunteered  the  information. 

At  several  points  more  particularly  along  the  north  shore  I 
found  marine  shells  (Lucina,  Tellina,  etc.)  imbedded  in  unques- 
tionable drift-rock,  and,  indeed,  it  could  hardly  have  been  ex- 
pected that  such  association  should  not  occur.  On  the  whole, 
however,  these  remains  were  not  as  abundant  as  one  might 
have  expected  to  find  them.  The  same  is  also  true  in  a 
measure  of  the  occurrence  of  land-snails.  One  of  the  com- 
monest shells  of  the  lower  drift-rock  is  the  large  Turbo  (Livona) 
pica, u  shell  which  appears  to  be  very  abundant  about  the  coast, 
but  which  generally,  and  perhaps  invariably,  is  cast  up  with- 
out the  animal.  I  was  unable  to  find  anyone  among  the  local 
collectors  who  had  seen  the  animal  itself,  nor  did  any  member 
of  our  party  succeed  in  obtaining  an  occupied  shell.  Nelson 
and  Rice  both  attribute  the  occurrence  of  this  shell  in  the 
drift-rock  to  transportation  by  hermit-crabs.  I  can  hardly  be- 
lieve that  this  is  the  full  explanation.  I  failed  to  find  any  of 
the  shells  of  the  beach  inhabited  by  hermits,  and  was  in  this 
respect  less  fortunate  than  Nelson,  nor  do  I  know  of  any  her- 
mit of  the  islands  which  would  be  likely  to  carry  about  with 
it  the  massive  full-grown  shell.  However,  my  testimony  on 
this  point  is  purely  negative. 

I  admit  with  Prof.  Rice  that  it  is  frequently  difficult 
to  distinguish  between  what  is  assumed  to  be  beach-rock  and 
the  regular  drift-rock  of  the  islands,  especially  when  the  latter 
occupies  a  basal  and  nearly  horizontal  position.  In  many 
places  along  the  south  shore  where  the  beach-rock  is  exposed 
in  heavy  beds  it  occupies  but  a  limited  horizontal  space,  being 
succeeded  by  highly  inclined  drift-rock,  which  descends  to  the 
water-level.  This  succession  is  unexpected,  and  might  lead 
one  to  infer  that  there  have  been  local  differential  movements 
on  the  part  of  the  land.  But  of  course  this  need  not  have  been, 
and  doubtless  was  not,  the  case,  since  an  irregular  or  indented 
shore-line  undergoing  elevation  would  form  features  similar 


36  THE  BERMUDA  ISLANDS. 

substantially  to  those  which  are  here  presented.  That  is  to  say, 
the  raised  beach-line  would  be  an  interrupted  one — continuous 
possibly  along  an  inner  contour,  but  broken  on  the  outer  face, 
where  a  low-level  beach  would  mark  that  portion  of  the  shore 
which  had  last  risen.  In  this  way,  it  is  not  improbable  that 
much  of  the  interior  drifts  of  the  Bermudas  will  be  found  to 
be  underlaid  by  elevated  beach-rock,  and  that  a  continuity  of 
extent  actually  exists.  It  appears  to  me  that  geologists  have 
not  taken  sufficient  account  of  the  irregularities  in  an  ascending 
coast  line  as  factors  determining  the  positions  or  relative  al- 
titudes to  which  points  of  elevation  must  necessarily  attain. 
They  are  too  ready  to  interpret  the  obliquity  or  inclined  posi- 
tion of  marine  terraces  on  the  assumption  of  terrestrial  oscilla- 
tions. 

The  one  fact  above  all  others  which  immediately  appeals  to 
the  geologist  in  the  Bermudas  is  the  rapid  waste  which  the 
islands  are  undergoing  and  have  undergone  for  some  long 
past  period.  Everywhere  along  the  coast  we  have  evidences 
of  this  waste;  the  outer  cliffs,  the  cliffs  and  ledges  of  the  inner 
waters,  the  serially  disposed  islands  and  islets,  all  bear  witness 
to  a  common  annihilating  process.  Along  the  south  shore  the 
lesson  of  destruction  is  presented  on  the  most  impressive  scale, 
and  it  is  here  that  we  read  most  clearly  the  record  of  waste 
which  the  islands  have  undergone.  The  huge  cliffs  are  still 
being  undermined  and  are  still  crumbling,  but  they  are  merely 
the  remains  of  a  land-mass  that  at  one  time  projected  far  be- 
yond the  present  coast-line  into  the  sea.  This  is  clearly  shown 
by  the  disposition  of  the  drift-rock  of  which  they  are  composed, 
the  layers  of  which  in  most  places  decline  steeply  in  the  direc- 
tion of  the  land,  turning  their  basset  edges  to  the  sea. 
Manifestly,  the  cliffs  are  merely  the  inner  halves  of  dunes,  the 
outer  slopes  of  which  have  been  carried  away  by  the  sea.  The 
height  of  the  cliffs  indicates  dunes  of  great  extent,  but  it  will 
probably  never  be  told  at  what  point  in  what  is  now  sea  they 
originated,  and  how  much  they  have  lost  through  oceanic  ero- 
sion. Not  improbably  the  land  at  one  time  projected  at  least, 
as  far  southward  as  the  position  which  is  now  occupied  by  the 
crest  of  the  reef. 


PHYSICAL  HISTORY  AND  GEOLOGY.  37 

There  can  be  no  doubt,  it  appears  to  me,  as  Rein*  first  clearly 
demonstrated,  that  Harrington  Sound  is  not  the  lagoon  of  a 
marginal  or  secondary  atoll,  but  merely  a  hole  that  has  been 
cut  out  of  the  land  by  the  sea.  I  think  that  every  one  who 
has  seen  the  working  condition  of  the  water  in  the  Sound,  the 
undercut  ledges,  the  scattered  islands  and  rocks,  and  above 
all,  the  precipitous  cliffs,  which  appear  on  opposite  sides  of  the 
water,  and  show  an  arrangement  of  lamination  or  stratifica- 
tion similar  to  that  which. is  observed  in  the  cut  cliffs  of  the 
south  shore,  must  arrive  at  the  same  conclusion.  The  same 
is  manifestly  also  true  of  much,  if  not  the  greater  part,  of  Cas- 
tle Harbor,  which  still  retains  a  sea-ward  border  in  the  belt 
of  disrupted  land  which  forms  Castle  Point,  and  Castle,  Goat, 
Nonsuch,  and  Cooper's  Islands.  The  widening  or  expansion 
of  this  body  of  water  presents  itself  vividly  to  the  eye  of  the 
observer  stationed  on  an  eminence,  such  as  that  of  St.  David, 
whence  the  field  of  vision  takes  in  the  patches  of  separating 
and  separated  land  which  are  awaiting  the  hour  of  their 
destruction. 

Along  the  borders  of  Castle  Harbor — at  least  as  far  as  we 
observed  it  on  the  west  and  south — there  is  a  broad  flat  ledge, 
over  which  the  depth  of  water  is  only  from  about  six  to  ten 
feet ;  beyond  this  there  is  an  abrupt  drop  into  the  deeper  parts 
of  the  lagoon.  This  feature  is  frequently  found  in  the  true 
atoll-lagoons,  where  it  forms  a  shore  platform  similar  to  that 
which  is  formed  around  the  outer  surfaces  of  sea-cliffs.  In 
how  far  this  ledge  may  represent  a  simple  coral  outgrowth 
from  the  shore,  or  determine  a  measure  of  subsidence,  can- 
not well  be  ascertained.  Large  numbers  of  giant  brain -corals 
('Mreandrina  and  Diploria),  measuring  three,  four,  and  five 
feet  in  diameter,  are  scattered  over  it,  and  form  a  series  of 
stepping  stones  in  the  water.  Many  of  them  grow  on  and 
over  the  edge  of  the  platform,  so  that  the  latter  overhangs  in 
some  places.  These  corals  appear  to  be  absent,  or  at  least 

*Bericht  Senckenberg.  Naturf.  Gtsellsch.,  1870,  p.  153. 


38  THE  BERMUDA  ISLANDS. 

largely  wanting,  in  the  deeper  waters.  We  sounded  at  various 
points  in  5-6  fathoms,  and  whether  this  represents  a  general 
depth  or  not,  it  is  certain  that  the  basin  is  far  shallower  than 
that  of  Harrington  Sound. 

Tn  the  pinnacles  of  the  North  Rock  we  have  probably  the 
most  imposing  lesson  touching  upon  the  annihilation  of  the 
land-mass.  The  lower  portion  of  these  rocks  is,  I  believe,  un- 
questionably of  beach  formation ;  I  failed  to  detect  in  it  the 
fossils  (Cyprraas,  etc.)  which  Rein  asserts  are  to  be  found  there, 
but  possibly  my  search  was  not  sufficiently  systematic  to  bring 
them  to  light.  This  basal  portion  of  the  rock  is  exceedingly 
tough  and  compact,  and  rings  loudly  when  struck  with  a  ham- 
mer. The  upper  moiety  is  made  up  of  distinctly  laminated  or 
stratified  drift-rock,  which  dips  at  a  steep  angle.  Manifestly, 
the  materials  of  this  raolian  formation  must  have  had  some 
starting  ground,  and  could  not  have  been  developed  from  the 
small  area  which  is  exposed  at  low  water  about  the  base  of  the 
pinnacles.  The  height  to  which  the  well-indurated  drift  at- 
tains, some  twelve  feet  or  more,  taken  in  conjunction  with  the 
vertical  reduction  which  the  rock  must  necessarily  have  under- 
gone, and  the  destruction  which  has  ensued  elsewhere,  argues 
almost  overwhelmingly  for  considering  these  fragments  to  be 
merely  the  remains  of  a  land-mass  which  had  at  onetime  very 
considerable  extent,  and  not  improbably  actually  united  with 
the  main  islands.  The  work  of  destruction,  according  to  this 
interpretation,  may  have  wiped  from  existence  a  piece  of  terri- 
tory possibly  not  inferior  in  area  to  that  which  is  now  exposed 
above  water. 

In  view  of  the  rapid  destruction  which  the  islands  are  under- 
going it  remains  to  inquire  what  are  or  were  the  special  condi- 
tions which  have  permitted  this  destruction  |to  take  place,  and 
have  so  completely  reversed  the  history  of  the  archipelago. 
For  evidently  the  conditions  under  whicli  the  islands  were 
first  built  up,  and  which  permitted  them  to  acquire  their  full 
development,  must  have  been  very  different  from  those  which 


PHYSICAL  HISTORY  AND  GEOLOGY.  39 

are  to-day  bringing  about  only  annihilation.  In  order  to  trace 
these  changes  it  is  first  necessary  to  determine  in  how  far  the 
present  outline  or  area  of  the  Bermudas  is  a  permanent  one,  or 
in  how  far  it  may  have  varied  during  the  period  of  its  exist- 
ence. By  geologists,  generally,  the  island  group  is  considered 
to  represent  the  disrupted  parts  of  an  atoll-ring,  most  of  which 
(as  is  seen  in  the  northern  reef)  now  lies  submerged  beneath 
the  water.  This  is  the  view  which  is  upheld  by  Dana  in  his 
"  Corals  and  Coral  Islands"  (p.  218)  and  by  the  late  Sir 
Wyville  Thomson  in  his  work  on  "The  Atlantic."  The  latter 
states*  that  the  character  of  the  Bermuda  atoll  "  is  much  the 
same  as  that  of  like  reefs  in  the  Pacific,  with  certain  peculiari- 
ties depending  upon  the  circumstance  that  it  is  the  coral 
island  farthest  from  the  equator,  almost  on  the  limit  of  the 
region  of  reef-building  corals."  The  atoll  character  of  the 
island  group  is  also  conceded  by  Prof.  Rice,  but  this  authority 
carefully  distinguishes  between  the  present  outlines  and 
those  which  belonged  to  the  original  atoll ;  he  recognizes 
movements  of  elevation  and  subsidence,  which  have  practically 
obliterated  the  normal  form  of  the  atoll,  and  have  left  it  in  a  con- 
dition where  there  need  be  no  necessary  correspondence  exist- 
ing between  the  present  land-masses,  with  the  submerged 
reef,  and  the  primary  atoll-ring.  The  condition  is  thus  stated 
by  him :  "  The  series  of  movements  required  to  account  for 
the  main  features  of  Bermudian  geology  seems  to  be  the 
following:  1.  A  subsidence,  in  which  the  original  nucleus  of 
the  islands  disappeared  beneath  the  sea,  the  characteristic  atoll 
form  was  produced,  and  the  now  elevated  beach-rock  was  de- 
posited. 2.  An  elevation,  in  which  the  great  lagoon  and  the 
various  minor  lagoons  were  converted  into  dry  land,  and  the 
vast  accumulations  of  wind-blown  sand  were  formed,  which 
now  constitute  the  most  striking  peculiarity  of  the  is-lands.  3. 
A  subsidence,  in  which  the  soft  drift-rock  around  the  shores 
suffered  extensive  marine  erosion,  and  the  shore  platform  and 

*Op.  cit.y     I,  p.  302. 


40  THE  BERMUDA  ISLANDS. 

cliffs  already  described  were  formed.  '  With  this  conception 
the  atoll  practically  disappears,  since,  in  the  absence  of  atoll 
characters,  there  is  nothing  to  indicate  that  the  structure  was 
ever  present ;  at  any  rate,  its  existence  is  rendered  purely 
hypothetical. 

Darwin  discusses  the  subject  with  his  usual  perspicuity,  and 
finds  reason  to  doubt  that  the  islands  are  a  true  atoll.  He 
points  out  their  close  general  resemblance  to  an  atoll,  but  in- 
dicates the  following  important  differences:  "  first,  in  the  mar- 
gin of  the  reef  not  forming  a  flat,  solid  surface,  laid  bare  at 
low  water,  and  regularly  bounding  the  internal  space  of  shal- 
low water  or  lagoon ;  secondly,  in  the  border  of  gradually 
shoaling  water,  nearly  a  mile  and  a  half  in  width,  which  sur- 
rounds the  entire  outside  of  the  reef;  and  thirdly,  in  the  size, 
height,  and  extraordinary  form  of  the  islands,  which  present 
little  resemblance  to  the  long,  narrow,  simple  islets,  seldom  ex- 
ceeding half  a  mile  in  breadth,  which  surmount  the  annular 
reefs  of  almost  all  the  atolls  in  the  Indian  and  Pacific  oceans." 
The  great  height  of  the  land,  as  compared  with  other  islands, 
is  also  commented  upon. 2 

In  all  these  characters  the  Bermudas  unquestionably  dif- 
fer from  a  typical  atoll,  but  allowing  for  the  conditions  which 
Prof.  Rice  suggests  these  differences  lose  much  of  their  signifi- 
cance. They  are  not  antagonistic  to  the  notion  of  an  overdone 
atoll  which  is  now  undergoing  destruction.  But  it  is  difficult^ 
if  not  impossible,  to  demonstrate  the  atoll  condition  itself. 
If  it  ever  existed  it  has  been  completely  masked  by  overgrowth, 
for  I  believe  the  facts  such  as  they  are  show  with  sufficient 
clearness  that  the  present  islands  and  reefs  have  little  or  noth- 
ing in  common,  beyond  occupying  position,  with  a  pre-existent 
ring.  Matthew  Jones  has  well  argued3  that  a  bodily  uplift  of 

1  Geol.  of  Bermuda.     Bull.  U.  S.  National  Museum,  No.  25,  pp.  16-17. 

2  Structure  and  Distribution  of  Coral  Reefs,  1842,  p.  204. 

3  Nature,  Aug.  1,  1872. 


PHYSICAL  HISTORY  AND  GEOLOGY.  41 

some  50  or  GO  feet  would  lay  dry  practically  the  whole  archi- 
pelago, as  far  as  the  great  northern  reef.  That  such  a  condi- 
tion of  elevation  at  one  time  existed  is,  I  believe,  all  but  de- 
monstrable ;  and  if  this  is  true  the  present  condition  can  only 
be  accounted  for  on  one  or  two  hypotheses :  simple  erosion  or 
erosion  in  combination  with  subsidence.  The  vast  amount  of 
erosion  that  has  taken  place  has  already  been  referred  to,  and 
it  is  barely  necessary  to  enter  further  into  its  details.  It  will 
immediately  suggest  itself  to  the  inquiring  mind  that  this  ero- 
sion could  not  well  have  taken  place  without  subsidence,  other- 
wise it  would  be  difficult  to  conceive,  except  under  a  condition 
of  very  rapid  elevation,  how  material  could  have  initially  ac- 
cumulated, so  as  to  lend  itself  to  destruction  afterward.  To 
assume  rapid  elevation,  followed  by  a  period  of  stability  when 
destruction  would  exceed  construction,  requires  the  formula- 
tion of  caupes  which  are  not  less  difficult  to  receive  than  those 
which  would  explain  subsidence.  Unquestionable  evidences  of 
subsidence  are,  however,  by  no  means  wanting,  and  coincident- 
ally  they  point  to  an  amount  of  movement  which  would  account 
approximately  for  the  depth  of  the  great  lagoon.  Thus,  in  the 
excavations  made  on  Ireland  Island  for  the  lodgement  of  the 
great  floating  dock,  a  deposit  of  peat,*  and  vegetable  soil  contain  - 
ing  stumps  of  cedar  in  a  vertical  position,  together  with  other 
vegetable  remains,  and  shells  of  the  common  sub-fossil  land- 
snail  of  the  islands,  were  found  at  a  depth  beneath  the  water 
of  some  45  to  50  feet.  The  depth  of  the  peat-bog  which  occu- 
pies the  central  part  of  Main  Island,  has  already  been  noticed. 
It  seems  to  be  a  not  uncommon  occurrence,  as  we  were  in- 
formed by  the  keeper  of  the  light  at  St.  David's,  that  stumps 
and  roots  of  cedars  are  drawn  up  by  the  anchor  chains  of  ves- 
sels riding  in  the  waters  about  St.  George's. 

The  caves  of  Bermuda  afford  equally  conclusive  evidence  of 
subsidence.  Many  of  these  now  occupy  a  level  considerably 
below  that  of  the  sea,  and  consequently  receive  a  large  in- 

*Thomson  :  "  The  Atlantic,"  I,  p.  320. 


42  THE  BERMUDA  ISLANDS. 

draught  of  water  from  that  source.  In  the  very  beautiful  Island 
Cave,  near  Joyce's  Dock,  on  the  north  shore,  the  interior  pool 
has  a  depth  of  probably  upwards  of  twenty  feet — we  were  in- 
formed that  it  was  thirty  feet — yet  through  it  rose  a  ponderous 
stalagmite,  several  feet  in  thickness.  Manifestly,  this  stalag- 
mite could  only  have  been  formed  when  the  pool  was  riot  yet 
existent  or  at  a  time  when  the  floor  of  the  cave  was  elevated 
above  sea-level.  The  depth  of  the  pool,  then,  is  a  measure  of 
the  least  possible  amount  of  subsidence,  from  20  to  30  feet  in 
the  present  instance.  Much  the  same  condition  is  presented 
by  some  of  the  other  caves.  These  sea-grottoes  are  among  the 
most  attractive  features  of  the  Bermudas,  and  they  would, 
even  in  regions  far  famed  for  their  caves,  attract  attention. 
The  principal  vaults  are  of  fairly  large  size,  but  the  connect- 
ing passages  are  low  and  contracted,  rendering  deep  penetra- 
tion difficult. 

These  various  forms  of  evidence  make  clear  that  there  has 
not  only  been  subsidence,  but  subsidence  on  a  moderately 
large  scale,  and  in  a  comparatively  recent  (geologically  speak- 
ing) period.  Indeed,  were  we  to  search  for  evidence  of  sub- 
sidence alone  we  would  not  be  compelled  to  go  beyond  the 
simple  drift-rock,  which  at  so  many  points  dips  directly  into 
the  sea.  To  what  amount  this  subsidence  may  have  extended 
cannot  in  the  nature  of  things  be  determined,  but  it  appears 
to  have  been  at  least  sufficient  to  account  for  the  depth  of 
water  which  marks  the  lagoon  and  inner  sounds.  Before  this 
subsidence  took  place  probably  the  entire  area  now  covered  by 
the  Bermudian  archipelago,  and  much  more,  were  dry  land, 
and  it  was  at  this  time,  doubtless,  that  the  great  sand  dunes 
were  elevated.  The  prevalence  of  powerful  winds  on  the  south 
side  would  tend  to  elevate  this  side  of  the  island,  while  the 
opposite  side,  not  feeling  this  influence  in  any  marked  degree^ 
would  remain  comparatively  low  and  flat.  In  a  period  of  sub- 
sidence the  low  side  would  naturally  be  the  first  to  succumb 
to  the  waters,  and  would  undergo  submergence  long  before 
the  elevated  slopes.  And  this  is  precisely  what  appears  to  have 
taken  place  in  the  Bermudas. 


PHYSICAL  HISTORY  AND  GEOLOGY.  43 

It  becomes  an  interesting  question  to  ascertain  how  far 
elevated  above  water-line  the  Bermudas  were  at  the  time  when 
they  formed  a  continuous  island.  The  data  that  are  presented 
for  the  determination  of  this  problem  are  mainly  of  a  negative 
character.  But  if  a  subsidence  of  some  50  or  60  feet  can  be 
indicated,  and  we  still  have  beach-rock  on  the  islands  at  an 
elevation  of  some  12-1G  feet,  it  will  be  necessarily  assumed 
that  the  actual  uplift  above  sea-level  was  at  least  60  or  70  feet, 
unless,  indeed,  the  movement  was  not  a  uniform  or  coincident, 
one  for  the  entire  island  group.  This  last  assumption  seems, 
however,  highly  improbable.  It  may,  again,  be  assumed  that 
the  elevated  beach-rock  was  lifted  since  the  period  of  sub- 
sidence, and  represents  the  closing  movement  of  the  land. 
Its  presence  therefore  need  not  argue  for  elevation  beyond  that 
which  is  indicated  b)  its  own  highest  level,  some  twelve  or 
fifteen  feet.  But  the  relation  of  this  rock  to  the  drift-rock 
overlying  it,  and  the  fact  that  the  latter  in  so  many  places 
drops  bodily  into  the  sea,  forbid  such  a  conception.  The 
beach-rock  is  manifestly  old,  and  long  antedates  the  last  sub- 
sidence; and  for  anything  that  can  be  shown  to  the  contrary, 
it  is  at  least  as  ancient  as  the  lagoons  and  sounds,  and  probably 
much  more  ancient.  Indeed,  there  is  nothing  that  could  lead 
one  to  suppose  that  it  is  not  the  original  rock  which  was 
formed  when  the  island  first  came  to  the  surface.  Although 
now  exposed  on  the  sea-border,  it  is  really  an  interior  rock,  as 
is  proved  by  the  broad  band  of  land  which  must  have  been 
removed  from  the  seaward  side  of  the  existing  cliffs. 

Two  questions  present  themselves  at  this  stage  of  the  inquiry. 
One  of  these  has  been  much  used  of  late  by  the  opponents  of 
the  Darwinian  theory  of  coral  formations,  and  bears  upon  the 
formation  of  lagoons  through  aqueous  solution.  The  second 
considers  the  amount  to  which  a  possibly  cavernous  condition 
of  the  island  may  have  facilitated  the  work  of  the  erosion,  and 
permitted  of  the  present  features  having  been  formed  without 
the  aid  of  subsidence. 


44  THE  BERMUDA  ISLANDS. 

No  one,  it  appears  to  me,  who  has  examined  any  of  the  in- 
ner waters  of  the  archipelago  can  for  a  moment  suppose  that 
the  basins  holding  these  waters  could  have  been  formed  or 
kept  open  through  solution  of  the  rock  supports.  Apart  from 
the  special  difficulties  which  the  Murray  theory  carries  with  it, 
and  which  will  be  found  more  extensively  discussed  in  the 
general  chapter  treating  of  the  formation  of  coral  structures, 
the  facts  presented  by  the  Bermudas  are  such  as  to  im- 
mediately dispose  of  the  theory  in  so  far  as  it  is  made  applica- 
ble to  them.  The  material  resulting  from  rock  degradation 
which  finds  its  way  into  the  waters  of  the  different  lagoons 
vastly  exceeds  in  quantity  that  which  could  possibly  be  re- 
moved through  solution ;  hence  we  have  the  entire  floor 
covered  with  a  thick  deposit  of  ooze,  as  our  dredgings  invaria- 
bly proved,  and  not  an  exposure  of  bare  rock  as  we  should  ex- 
pect to  find  in  a  basin  of  solution.  Organic  material,  largely 
foramini  feral,  is  also  accumulating  over  the  floor,  and  the  sup- 
ply of  formative  material  from  this  source  alone  is  probably 
fully  equal  to  that  which  is  removed  chemically  by  the  waters. 
The  quantity  of  this  basal  sediment  is  so  great  that  during  a 
heavy  storm,  as  was  witnessed  by  Rein  and  others,  the  entire 
water  reaching  to  the  outer  reef  was  rendered  milky  white.  As 
regards  the  second  question,  the  influence  of  a  cavernous  struct- 
ure upon  the  erosion  of  the  land,  the  facts  are  not  readily  ap- 
proached. Mr.  Fewkes,  in  a  paper  recently  published*  on  the 
"  Origin  of  the  Present  Form  of  the  Bermudas,"  argues  that 
the  existing  relations  of  the  archipelago  are  not  necessarily 
the  result  of  subsidence  (although  he  admits  that  the  evidences 
of  subsidence  are  unmistakable),  but  of  normal  erosion,  assisted 
by  the  breakages  which  in  one  form  or  another  are  likely  to 
follow  the  honeycombing  of  the  rock.  Caves  or  long  passages 
are  assumed  to  penetrate  into  all  parts  of  the  islands,  and  by 
their  collapse  are  supposed  to  furnish  the  hollows  which  ulti- 
mately form  the  lagoon-basin.  This  idea  is  not  entirely  new, 
and  was  already  entertained  by  Rein. 

*Proc.  Boston  Soc.  Natural  History,  1888,  pp.  518  et  seq. 


PHYSICAL  HISTORY  AND  GEOLOGY.  45 

A  number  of  serious  objections  present  themselves  to  the 
acceptance  of  this  explanation.  The  premises  are  largely,  if 
not  almost  wholly,  of  a  hypothetical  character.  That  the 
islands  are  in  a  measure  undermined  there  can  be  no  doubt, 
but  there  is  little,  if  anything,  to  show  that  there  have  been 
breakages  of  the  extent  which  would  be  required  by  the 
theory.  Evidences  of  local  disruption  are  plentiful,  such  as 
may  be  found  in  almost  every  region  of  sinks,  but  as  far  as  I 
can  see  there  is  nothing  to  indicate  that  basins  such  as  Har- 
rington Sound,  Castle  Harbor,  or  the  great  lagoon  could  have 
been  formed,  or  even  materially  furthered,  by  disturbances 
such  as  the  cave-theory  calls  into  existence.  The  even  floors 
of  these  basins  argue  strongly  against  formation  through 
breakage,  as  does  likewise  the  horizon tality  of  the  beach-rock 
formation.  The  absence  of  all  indications  of  disturbance 
from  the  latter  is  significant.  But  the  broader  question  can 
well  be  asked  :  How  could  extensive  cave  formations,  extending 
40,  60,  or  70  feet  beneath  the  water  surface,  be  brought  about 
without  subsidence  ?  Whence  would  the  force  of  excavation  be 
obtained  ?  The  answer  might  be  returned :  solution.  But 
there  is  no  more  reason  to  assume  special  solution  in  the  case 
of  the  Bermudas  or  in  other  coral  islands  than  in  any  marine 
limestone  formation. 

The  difficulty  in  the  problem  entirely  disappears  if  we  admit 
subsidence,  and,  as  has  already  been  seen,  the  positive  evidences 
of  subsidence  are  ample.  On  no  other  theory,  it  appears  to 
me,  can  the  waste  of  the  cliffs  on  the  south  shore  be  explained. 
The  direct  evidences  of  subsidence,  moreover,  do  not  come 
from  a  single  point  in  the  archipelago ;  they  are  found  from 
Ireland  Island  and  Hamilton  Sound,  through  the  Main 
Island,  to  St.  George's.  And  this  being  the  case,  there  is  every 
reason  to  assume  that  the  area  which  was  influenced  by  move- 
ments of  one  kind  or  another  was  not  restricted  to  the  present 
patches  of  exposed  land,  but  extended  to  the  submerged  por- 
tions of  the  archipelago  as  well. 


46  THE  BERMUDA  ISLANDS. 

As  the  result  of  our  researches  we  may  express  the  follow- 
ing conclusions: 

1.  The  present  form  of  the  Bermuda  Islands  bears  no  relation 
to  the  ring  of  an  atoll,  except  in  so  far  as  the  outer  boundary 
may  be  more  or  less  coincident  with  the  boundaries  of  an 
ancient  atoll. 

2.  The  existence  of  an  atoll  in  the  present  position  of  the  Ber- 
mudas is  not  demonstrable. 

3.  The  height  of  land  in  the  archipelago  was  formed  during 
a  period  of  elevation,  when  seemingly  the  entire  archipelago 
was  a  connected  or  continuous  piece  of  land,  extending  as  an 
oval  island  to  what  is  now  the  bounding  reef  on  the  north 
and  on  the  south.     It  is  impossible  to  determine  the  absolute 
amount  of  elevation  above  the  water,  but  it  appears  to  have 
been  not  less  than  70  or  80  feet,  and  it  may  have  been  con- 
siderably more. 

4.  The  lagoons  and  sounds  were  formed  duringa  period  of  sub- 
sidence which  followed  upon  that  of  elevation,  and  is  seemingly 
still  in  progress,  or  was  so  until  a  comparatively  recent  period. 
The  great  degradation  of  the  coast-lime  took  place  at  this  time. 
It  is  impossible  to  determine  the  amount  of  such  subsidence, 
but  it  was  at  least  60-70  feet,  and  not  improbably  very  much 
more. 

It  will  be  seen  that  these  results,  so  far  as  they  go,  are  in  ab- 
solute harmony  with  the  views  which  Mr.  Darwin  entertained 
regarding  the  structure  of  these  islands.  They  do  not  prove 
the  correctness  of  the  Darwinian  hypothesis  of  the  formation 
of  coral  islands,  but  they  measurably  sustain  it ;  on  the  con- 
trary, they  are  largely  opposed  to  the  requirements  of  the  sub- 
stitute theory  which  has  been  recently  proposed.  Elevation 
and  subsidence  are  both  shown  to  have  marked  the  region  in 
its  development,  and  these  conditions  are  more  in  consonance 
with  the  Darwinian  hypothesis  than  with  any  other. 


PHYSICAL  HISTORY  AND  GEOLOGY.  47 

The  question  as  to  what  form  of  coral  structure  the  Bermu- 
das actually  are — what  constitutes  their  fundament,  and  how 
they  were  built  to  their  existing  level — still  remains  un- 
answered, and  possibly  we  may  never  be  able  to  answer.  But 
I  have  thought  it  worth  while  to  introduce  a  discussion  of  the 
general  coral  question  (the  chapter  following),  as  it  has  a  bear- 
ing on  the  topic  at  issue. 


IV. 


THE  CORAL-REEF  PROBLEM. 


Perhaps  no  class  of  phenomena  has  been  so  frequently  ap- 
pealed to  in  evidence  of  subsidence  on  a  grand  scale  as  that 
presented  in  the  formation  of  coral  reefs.  Scattered  freely  over 
a  large  expanse  of  the  oceanic  surface,  these  structures  consti- 
tute features  there  as  distinctive  and  prominent  as  do  the 
mountain  masses  on  the  continents.  Rising  in  most  cases 
from  a  deep  sea,  and  with  a  limited  extent,  their  presence,  as 
organic  accumulations,  immediately  suggests  peculiarities  of 
geological  construction  which  are  to  be  found  in  no  other 
form  of  relief.  It  is  an  ascertained  fact,  as  has  been  variously 
demonstrated  that  the  conditions  governing  the  existence  and 
distribution  of  reef-building  corals  (Porites,  Diploria,  Msean- 
drina,  Madrepora,  Tubipora,  Fungia,  Astrsea,  etc.)  are  drawn 
within  narrow  limits,  and  that  they  are  equally  of  a  general 
and  of  a  special  character.  Broadly  stated  these  conditions 
are  :  A  surface  temperature  of  the  water  never  falling  below 
70°  or  68°  F. ;  an  absence  of  muddy  sediment ;  freedom  from 
contact  with  fresh  waters ;  the  necessity,  in  some  cases,  of  surf 
action.  Accordingly,  we  find  that  reef-structures  are  practi- 
cally confined  to  the  warm  tropical  or  subtropical  seas,  and 
that  they  are  largely  wanting  in  tracts  where  exceptional  cold 
currents  have  wedged  a  path  into  the  warmer  waters,  or  where, 
as  at  the  mouths  of  outflowing  streams,  there  is  a  free  dis- 
charge of  both  freshwater  and  sediment.  To  this  must  be  ad- 
ded the  all-important  fact  that  the  reef-building  corals  are  con- 
fined to  a  superficial  zone  of  the  sea  not  exceeding  100  or  120 


ROAD-CUT   IN   ^OLIAN    ROCK. 


Le> 


THE  CORAL-REEF  PROBLEM.          49 

feet ;  beyond  this  depth  we  meet  only  with  dead  coral.  In 
the  case  of  the  Bermudas,  and  in  that  of  a  few  other  reefs, 
the  temperature  of  the  water  has  been  known  to  descend  to  66° 
or  even  64°  F.,  but  this  condition  is  very  exceptional. 

One  of  the  most  familiar  and  wide-spread  types  of  coral 
structure  is  the  atoll,  which  acquires  special  development  in 
the  waters  of  the  Pacific  and  Indian  oceans.  It  consists  of  a 
more  or  less  irregular  ring  of  living  and  dead  coral,  enclosing 
within  its  boundaries  an  internal  body  of  water  (lagoon),  which 
in  many  cases  is  kept  in  direct  communication  with  the  ex- 
terior by  one  or  more  connecting  channels  of  water ;  the  breaks 
in  the  ring  corresponding-'to  these  passages  almost  invariably 
occur  on  the  leeward  side  of  the  island.  The  atoll,  although 
frequently  so  described, -is  rarely  of  a  circular  form,  the  outline 
being  very  generally  elongated  and  angular.  In  extent  it 
varies  from  two  to  three  miles,  or  less,  in  length  to  upwards  of 
40  or  50  miles ;  where  the  dimensions  are  very  small  the  lagoon 
may  be  completely  absent,  or  merely  indicated  by  a  dry  de- 
pression. The  breadth  of  the  coral  ring  itself  dx)es  not  usually 
exceed  1000-1500  feet,  or  somewhat  more  than  a  quarter  of  a 
mile.  In  the  general  composition  of  an  atoll,  the  following 
parts  may  be  recognized  :  first,  an  outer  platform  of  coral-rock, 
more  or  less  exposed  at  low  water,  which  is  the  correspondent 
of  the  ordinary  rock  platforms  resulting  from  tidal  destruction  ; 
secondly,  the  beach-line  proper,  measuring  a  few  feet  in  height, 
and  consisting  of  coral  sand,  calcareous  pebbles,  and  triturated 
shells;  and  thirdly,  the  exposed  ring  itself  with  the  width  as 
above  stated,  over  which,  more  especially  on  the  windward  side, 
a  luxuriant  vegetable  growth  is  developed.  The  elevation  of 
this  portion  of  the  atoll  more  commonly  does  not  exceed  10-20 
feet,  although  exceptionally  the  wind-swept  dunes  of  coral  sand 
attain  a  much  greater  height.  On  some  islands,  not  necessarily 
atolls,  however,  as  Anegada,  one  of  the  West  Indies,  the  drift 
banks  rise  to  a  height  of  40  feet,  while  on  the  Bermudas  they 
considerably  exceed  200  feet,  reaching  at  one  point,  Sears' 
Hill,  260  feet. 


50  THE  BERMUDA  ISLANDS. 

On  the  lagoon  side  of  the  ring  the  shore-platform  is  very 
commonly  replaced  by  a  gently  sloping  sand  bottom,  with  or 
without  the  formation  of  a  true  beach  area.  Frequently  there 
juts  out  from  the  shore  a  growing  reef-platform  (upon  which 
the  coral  growth  is  fairly  profuse),  which  descends  with  a 
vertical  or  overhanging  edge  to  a  second  deeper  zone  of  coral 
life.  Over  the  bottom,  which  presents  a  more  or  less  uniform 
character,  coral  sand  and  debris,  calcareous  pebbles,  the  tests 
of  various  Foraminifera,  etc.,  are  extensively  distributed,  form- 
ing there  a  sticky  white  or  bluish  paste,  much  like  that  which 
extends  for  miles  beyond  the  outer  border  of  the  forming  reef. 
The  depth  of  the  lagoons  varies  from  a  few  feet  to  twenty  or 
thirty  fathoms,  as  we  find  it  in  many  island  groups  of  the 
Pacific  (Paumotu,  Gilbert's  Group,  Keeling  Island,  etc.).  In 
the  Maldives  it  exceptionally  attains  50  and  GO  fathoms. 

As  reef-building  corals  cannot  long  survive  exposure  to  the 
atmosphere  it  is  manifest  that  the  upper  limit  of  the  growing 
mass  will  be  the  actual  surface  of  low-water.  In  the  line  of 
the  breakers,  or  in  the  shallows  just  beyond,  the  coral  polyps 
thrive  in  their  greatest  profusion,  and  the  almost  end- 
less variety  of  their  forms,  not  less  than  their  brilliant  color- 
ing, never  fails  to  arouse  the  wonder  and  enthusiasm  of  the 
traveler.  Prof.  Dana  thus  graphically  describes  the  forming 
island  :  "  The  reef  of  the  coral  atoll,  as  it  lies  at  the  surface 
still  uncovered  with  vegetation,  is  a  platform  of  coral  rock, 
usually  two  to  four  hundred  yards  wide,  and  situated  so  low 
as  to  be  swept  by  waves  at  high  tide.  The  outer  edge,  directly 
exposed  to  the  surf,  is  generally  broken  into  points  and  jagged 
indentations,  along  which  the  waters  of  the  resurging  wave 
drive  with  great  force.  Though  in  the  midst  of  the  breakers, 
the  edge  stands  a  few  inches,  and  sometimes  a  foot,  above 
other  parts  of  the  platform ;  the  incrusting  nullipores  cover  it 
with  varied  tints,  and  afford  protection  from  the  abrading 
action  of  the  waves.  There  are  usually  three  to  five  fathoms 
water  near  the  margin ;  and  below,  over  the  bottom,  which 
gradually  deepens  outward,  beds  of  coral  are  growing  pro- 


THE  CORAL-KEEF  PROBLEM.  51 

fusely  among  extensive  patches  of  coral  sand  and  fragments. 
Generally  the  barren  areas  much  exceed  those  flourishing  with 
zoophytes,  and  not  infrequently  the  clusters  are  scattered  like 
tufts  of  vegetation  in  a  sandy  plain.  The  growing  corals  ex- 
tend up  the  sloping  edge  of  the  reef,  nearly  to  low-tide  level. 
For  ten  to  twenty  yards  from  the  margin,  the  reef  is  usually 
very  cavernous  or  pierced  with  holes  or  sinuous  recesses,  a  hid- 
ing place  for  crabs  and  shrimps,  or  a  retreat  for  the  Echini', 
Asterias,  sea-anemones,  and  mollusks.  *  *  *  Further  in  are 
occasional  pools  and  basins,  alive  with  all  that  lives  in  these 
strange  coral  seas." 

This  description,  which  is  drawn  from  the  islands  of  the 
Pacific,  is  largely  applicable  to  the  condition  of  the  Bermudas. 
Owing  to  the  peculiar  submerged  condition  of  the  reef  I  was 
unable  to  determine  satisfactorily  to  what  extent  a  breaking 
surf  was  favorable  or  unfavorable  to  the  growth  of  corals.  At 
the  North  Rock,  the  only  accessible  point  of  the  outer  reef,  the 
millepore  growth  is  very  profuse,  and  large  masses  of  Porites 
may  be  picked  out  from  below  the  capping  of  serpula.  The 
same  condition  prevails  over  the  Devonshire  Flatts,  where  the 
surf  dashes  over  a  wilderness  of  atoll-like  islets  scattered 
through  the  lagoon.  But  this  is  not  necessarily  evidence  in 
favor  of  advantage  derived  from  the  surf,  since  these  seemingly 
more  favored  patches  are  the  creators  of  the  surf  themselves, 
and  they  must  have  risen  before  assistance  from  this  direction 
could  have  been  given  them.  Their  existence  seems  to  prove, 
however,  that  the  action  of  the  surf  is  no  disadvantage,  a  con- 
clusion opposed  to  that  which  was  reached  by  Bourne  from 
his  careful  studies  of  the  Diego  Garcia  Reef.*  Along  the 
inner  slope  of  the  reef,  immediately  receding  from  what  might 
be  called  the  crest,  as  well  as  on  both  slopes  of  the  serpula- 
capped  southern  reef,  the  coral  growth  appears  in  unbounded 
profusion,  presenting  a  perfect  maze  of  millepores,  gorgonias, 
and  brain-stones. 

*Proc.  Royal  Society,  XLIII,  1888,  pp.  453-55. 


52  THE  BERMUDA  ISLANDS. 

There  is  little  or  no  growth  of  coral  immediately  along  the 
south  shore,  doubtless  due  to  the  great  quantity  of  sediment 
that  is  constantly  being  washed  off  from  the  cliffs.  The  rocks 
of  Harrington  Sound,  on  the  other  hand,  are  largely  fringed 
with  patches  of  Isophyllia,  Siderastrsea,  and  Millepora,  while 
in  the  deep  quieter  waters,  judging  from  the  number  of  our 
hauls,  Oculina  is  by  no  means  scarce.  Reference  has  already 
been  made  to  the  vast  development  of  Diploria  and  Msean- 
drina  on  the  projecting  platform  of  Castle  Harbor,  over  which 
the  water  is  normally  in  a  condition  of  fair  stability.  This 
condition  confirms  the  view  expressed  by  Bourne  that  the 
coral  growth  of  the  inner  waters  is  much  more  extensive  than 
is  generally  stated  to  be  the  case.  A  very  large  part,  however, 
if,  indeed,  not  the  greater  part,  of  the  floor  of  the  big  lagoon 
is  practicallv  barren. 

Although  the  zone  of  animal  activity  in  a  coral  island  ceases 
with  the  water-line,  the  actual  growth  of  the  island  does  not  stop 
there,  but  is  continued  upward  by  the  mechanical  and  vegeta- 
ble forces.  The  destructive  action  of  the  billows  carries  frag- 
ments of  coral-rock  far  above  the  limits  of  coralline  existence, 
triturating  the  masses  into  minute  surfaces,  and  upon  this  im- 
provised soil  a  luxurious  vegetation,  whose  origin  lies  in  the 
seeds  wafted  thither  by  the  winds,  or  deposited  by  birds,  may 
in  course  of  time  spring  up.  Where  the  action  of  the  breakers 
is  greatest  the  coral  rock  assumes  the  greatest  compactness, 
since  the  fragments  and  particles  that  are  derived  from  the 
mechanical  wear  and  tear  are  here  firmly  lodged  or  compacted 
into  the  spaces  of  the  otherwise  comparatively  loose  coral 
structure.  On  the  oceanic  side  of  the  island  we  find  shallow 
water — ranging  to  several  hundred  feet — for  a  distance  of 
between  300  to  1500  feet,  beyond  which  the  descent  becomes 
rapid,  dropping  suddenly  to  several  thousand  feet.  At  a  dis- 
tance of  less  than  three-quarters  of  a  mile  from  the  Island  of 
Clermont  Tonnerre,  the  lead  was  run  out  to  a  depth  of  3,600 
feet,  and  yet  no  bottom  was  found :  at  a  distance  of  seven  miles 
a  run  of  6,000  feet  failed  to  strike  bottom.  Off  the  Cardoo 


THE  CORAL-REEF  PROBLEM.         53 

atoll  soundings  made  at  a  distance  of  60  yards  from  the  coast 
failed  to  detect  bottom  at  a  depth  of  1200  feet,  and  500  feet 
out  from  Whitsunday  Island  no  bottom  was  found  by  Beechey 
at  a  depth  of  1500  feet.  Captain  Fitzroy  found  that  at  a  dis- 
tance of  6,600  feet  from  the  Keeling  Island  shores  the  lead 
did  not  strike  bottom  even  after  having  been  run  out  to  a 
length  of  7,200  feet.  Seven  miles  to  the  north-west  of  the  Ber- 
muda reef,  as  has  already  been  seen,  the  depth  of  water  is 
2,100  fathoms,  but  the  coast  shallows  for  a  considerable  dis- 
tance around  the  islands.  It  would 'thus  appear  that  the 
pitch  of  the  coral  island  beneath  the  ocean  is  at  a  very  steep 
angle,  sometimes  considerably  exceeding  45  degrees.  Indeed, 
there  are  some  grounds  for  concluding  that  in  the  deeper 
parts  the  faces  are  nearly  vertical,  rising  like  gigantic  walls 
from  the  oceanic  abysses. 

In  view  of  the  peculiar  conditions  attending  coral  growth — 
the  limitation  of  depth  to  100  or  120  feet — the  difficulty  of  ac- 
counting for  the  occurrence  of  coral  structures  in  some  of  the 
deepest  parts  of  the  sea  at  once  becomes  apparent.  It  had,  in- 
deed, been  assumed  that  coral  islands  merely  occupied  the  sum- 
mits of  submerged  volcanoes,  and  that  their  distribution  over 
the  deep-sea  was  simply  an  indication  of  the  existence,  in  the 
region  in  question,  of  an  equal  number  of  buried  volcanic 
peaks  or  mountain  backs.  Recent  researches  have,  however, 
failed  in  the  majority  of  cases  to  detect  the  presence  of  such 
hypothetical  buttresses  rising  to  within  a  few  feet  of  the  sur- 
face, but,  on  the  contrary,  tend  to  show  that  at  least  in  some 
instances  the  actual  coral  portion  of  the  island  descends  of 
itself  hundreds,  if  not  thousands,  of  feet  into  the  ocean. 

The  genius  of  the  late  Mr.  Darwin  has  furnished  a  theoretical 
explanation  of  the  phenomenon  which,  even  if  it  cannot  be 
held  to  be  proved  or  con-elusive,  has  at  least  the  merit  of  a 
strong  probability  in  its  favor,  and  of  being  in  consonance 
with  well-determined  geological  facts  and  conditions.  This 
"subsidence"  theory,  which  until  recently  received  the  almost 
unanimous  support  of  geologists,  is  based  upon  the  evidence  of 


54  THE  BERMUDA  ISLANDS. 

extensive  terrestrial  movements,  and  presupposes  the  existence 
of  numerous  land-masses  rising  from  the  deepest  water.  Around 
these,  under  favorable  conditions,  reef-building  and  other  corals 
would  flourish  in  abundance,  the  submerged  cone  affording  a 
suitable  base  for  the  development  of  the  coral  animal.  The 
external  margin  of  the  coral  barrier  or  buttress,  which  may  be 
assumed  to  grow  from  a  possible  depth  of  120  feet,  owing  to  the 
invigorating  action  of  the  beating  surf,  and  an  increased  food- 
supply,  would  probabty  rise  more  rapidly  than  the  inner  parts, 
whose  development  would  also  in  a  measure  be  checked  by  the 
out-pouring  of  detrital  sediment.  A  shelving  inwardly -slop- 
ing collar  or  bank,  having  a  land-nucleus  in  its  center,  would 
thus  be  produced.  In  the  ring  thus  forming,  whose  outer  mar- 
gin, through  the  breaking  and  heaping  action  of  the  sea,  would 
be  lifted  somewhat  above  the  general  water-level,  we  have  the 
skeleton  of  the  future  atoll.  We  may  now  distinguish  three 
elements  in  its  construction  :  the  outer  ring  or  collar  of  coral, 
the  central  nucleus  of  land,  and  the  encircling  body  of  water 
which  separates  the  two. 

If  at  this  stage  of  its  formation  we  conceive  the  enclosed 
island  to  undergo  a  slow  and  gradual  subsidence  the  following 
phenomena  may  be  assumed  to  present  themselves.  The  outer 
border  of  the  reef  would  slowly  but  steadily  build  itself  up  to  the 
level  of  the  water,  the  growth  of  the  coral  colony  keeping  pace 
with  the  gradual  sinking  of  its  substratum,  provided  this  be  not 
too  rapid.  The  parts  sinking  below  the  line  of  120  feet  would  die 
out,  and  their  future  purpose  would  be  merely  to  afford  a  base 
for  the  super-structure.  The  island  portion,  on  the  contrary, 
would  sink  deeper  and  deeper,  until  eventually  it  might  com- 
pletely disappear.  We  would  then  have  an  outer  barrier  and 
an  inner  lagoon,  with  probably  one  or  more  communicating 
passages  between  the  latter  and  the  sea  cut  through  the  coral 
growth.  This  is  the  typical  atoll. 

When  a  reef  is  separated  by  a  considerable  body  of  water 
from  the  adjoining  land  it  is  termed  a  "  barrier  "  reef,  of  which 
two  distinct  types,  the  "encircling"  and  the  "linear"  barrier 


THE  CORAL-KEEF  PROBLEM.          55 

reef,  are  recognized.  An  encircling  barrier  reef  differs  mainly 
from  an  atoll  in  that  the  assumed  subsidence  has  not  been  suf- 
ficient to  completely  bury  the  enclosed  island,  leaving  con- 
sequently, no  internal  sea,  but  merely  a  separating  channel 
formed  within  the  coral  boundaryi  By  further  subsidence,  it 
is  conceived,  the  encircling  reef  would  be  converted  into  an 
atoll.  When  a  coral  boundary  extends  for  a  great  distance  in 
a  more  or  less  linear  direction  it  is  termed  a  linear  reef,  or 
"  barrier  "  reef  proper.  The  great  barrier  reef  off  the  island  of 
New  Caledonia  extends  in  a  N.  W.  and  S.  E.  direction  for  a  dis- 
tance of  upwards  of  400  miles,  and  that  of  the  northeastern 
coast  of  Australia  has  a  linear  extension,  with  interruptions  of 
more  than  1000  miles.  In  the  case  of  the  latter  the  width  of 
the  intervening  strait  is  in  many  places  between  50  and  60 
miles,  with  a  depth  of  water  reaching  350  feet.  The  reef 
patches,  themselves,  even  in  their  broader  parts,  rarely  exceed 
one  or  two  miles  in  width. 

Besides  the  three  forms  of  coral  structure — atolls,  encircling 
and  barrier  reefs — which  have  been  assumed  to  give  un- 
equivocal evidence  of  subsidence,  there  is  still  a  fourth  type, 
that  of  the  so-called  "fringing"  reef,  which  has  generally  been 
considered  to  afford  proof  either  of  terrestrial  stability  or  of 
actual  elevation.  These  fringing Teefs  hug  the  immediate  shore 
line,  and  may,  indeed,  be  said  to  represent  the  incipient  stage 
or  starting  point  whence  the  other  forms  of  reefs  were  developed  ; 
by  slow  subsidence  a  fringing  reef  would,  on  the  Darwinian 
hypothesis,  be  converted  into  a  barrier  reef.  Fringing  reefs  are 
frequently  continued  as  a  series  of  superimposed  terraces 
above  the  dry  land, — an  unequivocal  proof  of  elevation.  They 
rarely,  if  ever,  descend  in  the  water  to  depths  much  exceeding 
120  feet,  and,  as  might  be  naturally  supposed  from  their  man- 
ner of  formation,  are  but  rarely  associated  with  the  other  forms 
of  coral  reefs. 

Applying  the  Darwinian  hypothesis  of  subsidence  to  the 
phenomena  of  coral  structures  generally,  we  may  deduce  the 
following :  A  region  of  atolls,  encircling  and  barrier  reefs  is 


56  THE  BERMUDA  ISLANDS. 

primarily  a  region  vof  subsidence — of  subsidence  now  actually 
taking  place,  or  only  recently  completed-;  per  contra,  regions 
characterized  by  fringing  reefs  are  regions  either  of  stability  or 
of  slow  and  gradual  upheaval.  The  greatest  area  of  indicated 
subsidence  is  that  of  the  Central  Pacific,  which  has  been  as- 
sumed to  compass  a  tract  measuring  6000  miles  in  length  and 
2000  miles  in  greatest  width.  Commencing  at  the  Paumotu 
group,  or  the  Low  Archipelago  on  the  south-east,  and  extend- 
ing to  the  Carolines  on  the  north-west,  the  coral  structures  dot 
at  intervals  the  surface  of  the  sea  for  a  linear  distance  of  100 
degrees  of  longitude,  embracing  in  this  space  several  hundred 
true  islands,  besides  numerous  reefs  of  one  form  or  another. 
In  the  Paumotu  group  alone  there  are,  according  to  Dana,  not 
less  than  80  atolls. 

The  existence  of  such  an  enormous  subsidence  area  as  is  in- 
volved in  the  Darwinian  hypothesis  is  necessarily  difficult  to 
realize,  and,  indeed,  numerous  apparently  valid  objections 
seem  to  interpose  themselves  to  its  full  acceptance.  It  has  been 
shown  that  within,  or  immediately  on  the  border  of,  the  sup- 
posed subsiding  area  there  occur  local  tracts  where  fringing 
reefs  take  the  place  of  atolls ;  and,  again,  others  where  raised 
coral  patches  or  terraces  clearly  indicate  elevation.  The  coral 
on  some  of  the  Hervey  and  Friendly  islands  is  stated  to  oc- 
cur at  a  height  of  300  feet  above  sea-level ;  on  the  island  of 
Guan,  one  of  the  Ladrones,  according  to  Quoy  and  Gaymard, 
the  coral  rock  is  in  places  fully  600  feet  above  the  sea.  In 
some  island  groups,  as  Hawai,  Feejee,  etc.,  coral  structures  ap- 
parently indicative  of  both  depression  and  elevation  occur 
interassociated  among  the  different  islands  constituting  those 
groups,  and  the  same  feature — the  interassociation  of  fringing 
and  barrier  reefs  with  atolls — has  been  observed  by  Semper  in 
the  Pelew  Archipelago  (West  Pacific).  This  condition,  together 
with  various  concomitant  difficulties  that  lie  in  the  way  of  the 
Darwinian  hypothesis,  has  led  to  the  rejection  by  many 
naturalists— Semper,  Guppy,  A.  Agassiz,  Murray,  Geikie,  and 
others — of  the  subsidence-theory,  and  to  the  substitution  for 


THE  CORAL-REEF  PROBLEM.          57 

it  of  a  theory  of  simple  coral  upgrowth,  with  structural  modi- 
fications as  depending  principally  upon  currental  action  and 
food-supply. 

This  theory,  like  its  alternative,  presupposes  as  a  first  neces- 
sary condition  of  coral  growth  the  existence  of  a  submarine 
basement  within  the  zone  of  coral  life  (1-20  fathoms).  Upon 
this,  which  may  be  the  buried  slope  or  the  summit  of  a  volcano, 
or  merely  a  bank,  the  coral  animal  develops  and  builds  to  the 
surface.  Where  such  a  sub-structure  does  not  immediately 
exist,  or  rather  does  not  extend  to  the  zone  within  which  reef 
corals  are  limited,  it  is  claimed  that  suitable  foundations  may 
be  obtained  through  the  building  up  of  submarine  volcanoes  by 
the  deposition  on  their  summits  of  organic  and  other  sediments. 
This  would  explain  the  apparent  anomaly  of  coral  structures 
rising  from  depths  vastly  exceeding  the  lower  boundaries  of 
coral  growth,  a  condition  which  to  Mr.  Darwin  necessitated 
the  assumption  of  subsidence.  It  is  well  known  that  through- 
out the  greater  mass  of  the  ocean  there  is  a  constant  rain  or 
down-pouring  of  organic  particles  in  the  form  of  the  calcareous 
and  siliceous  tests  of  Foraminifera,  pteropods,  diatoms,  etc., 
much  of  which  goes  to  form  the  vast  accumulation  of  white 
mud  (Atlantic  or  Globigerina  ooze)  which  covers  the  greater 
part  of  the  oceanic  floor.  Manifestly,  such  an  accumulation 
must  eventually  acquire  great  thickness.  It  is  more  than 
doubtful,  however,  if  any  very  considerable  thickness  of  such 
deposit  has  been  built  up  during  the  existing  period  of  coral 
growth,  or  that  an  accumulation  of  this  kind  has  materially 
aided  in  building  up  the  sub-coral  buttresses  of  the  deeper 
seas.  The  investigations  of  Mr.  Murray,  deduced  from  data 
obtained  by  the  "  Challenger,"  indicate  that  a  column  of 
oceanic  water  of  600  feet  depth,  with  a  transverse  area  of  one 
square  mile,  contains  some  16  tons  of  suspended  organic  par- 
ticles; these,  if  precipitated  to  the  floor  of  the  sea,  would  make 
a  deposit  mfav  inch  in  thickness.  It  has  thus  far  been  im- 
possible to  determine  the  duration  of  life  of  the  organisms 
furnishing  the  organic  particles,  mainly  Foraminifera,  and 


58  THE  BERMUDA  ISLANDS. 

consequently  there  is  no  direct  way  of  ascertaining  in  what 
period  the  tests  of  a  given  column  of  water  are  replenished. 
But  manifestly,  there  can  be  no  more  rapid  accumulation  of 
the  calcareous  ooze  than  there  is  lime-carbonate  suspended  in 
the  sea;  and  again,  the  quantity  of  lime-carbonate  so  sus- 
pended must  depend  upon  the  quantity  of  the  formative 
material  contained  in  the  sea — the  quantity  of  lime  carried  in 
by  the  rivers,  and  any  residual  or  surplus  quantity  that  might 
be  already  existing.  Now,  it  would  seem  from  careful  obser- 
vation made  on  many  of  the  most  important  rivers  of  the 
globe  that  the  quantity  of  lime  carried  out  by  them  into  the 
sea  annually  is  about  one-sixth  that  of  their  suspended  sedi- 
ment, which  would  cover  the  sea-bottom,  if  precipitated  at  a 
rate  proportional  to  that  of  the  removal  of  continental  sedi- 
ment— one  foot  in  3000  years — to  a  depth  of  about  ¥7^0  inch. 
Assuming  that,  one-half  of  this  amount  is  used  by  the  Fora- 
minifera  for  the  construction  of  their  shells,  the  rest  being 
taken  up  by  the  mollusks,  corals,  etc.,  then  the  foraminiferal 
accumulation  from  this  source  would  be  the  ¥^  part  of  an 
inch  annually,  or  very  nearly  the  amount  that  would  accumu- 
late from  the  droppings  contained  in  the  600-foot  column  of 
water,  as  deduced  from  Mr.  Murray's  determination.  At  this 
extremely  slow  rate  of  accumulation,  it  would  require  a  period 
of  100,000  years  to  build  up  the  thickness  of  a  single  foot! 
Naturally  along  coast-lines,  where  the  molluscous  animals 
largely  contribute  to  the  general  growing  mass,  and  where  inor- 
ganic sedimentation  is  unusually  brisk,  the  process  of  upgrowth 
may  be  comparatively  rapid,  especially  in  the  trend  of  powerful 
oceanic  currents.  A  condition  of  this  kind  seems  to  obtain 
along  the  Floridian  coast,  and  it  is  not  unlikely,  as  has 
been  suggested  by  A.  Agassiz,  that  the  Florida  banks  have 
been  built  up  largely  in  the  manner  above  described.  But  the 
conditions  become  very  different  when  the  oceanic  abyss,  such 
as  the  central  Pacific,  is  substituted  for  a  comparatively  shallow 
coast-line.  Indeed,  even  in  the  case  of  the  Floridian  banks  it 
is  doubtful  if  most  of  their  upgrowth  is  not  really  due  to 


THE  CORAL-REEF  PROBLEM.          59 

bodily  uplift  rather  than  to  organic  and  inorganic  accumula- 
tion, as  we  have  most  conclusive  evidence  of  an  uplift  in  the 
peninsula  of  Florida  in  a  period  at  least  as  late  as  the  Plio- 
cene. Nor  are  evidences  of  a  more  recent  contrary  movement 
wanting  in  the  same  region. 

It  will,  however,  naturally  be  urged  against  this  assumption 
of  slow  accumulation  that  the  quantity  of  the  salts  of  lime 
already  contained  by  the  sea  is  vastly  in  excess  of  that  which 
is  annually  thrown  in  by  the  rivers,  and  that,  therefore,  the 
amount  of  formative  material  on  hand  is  amply  sufficient  to 
meet  all  the  exigencies  of  a  rapid  growth.  The  quantity  of 
calcium  actually  contained  in  every  cubic  mile  of  sea-water  is 
estimated  to  be  nearly  2,000,000  tons,  while  that  held  by  an 
equal  volume  of  river-water  is  less  than  150,000  tons.  At  the 
rate  of  the  present  carrying  capacity  of  rivers  it  is  calculated 
that  it  would  require  680,000  years  to  pour  into  the  ocean  an 
amount  of  calcium  equal  to  that  which  is  now  held  by  it  in 
solution.*  The  question  here  naturally  presents  itself:  To 
what  extent  is  this  surplus  quantity  of  lime  drawn  upon  by  the 
oceanic  organisms  for  the  construction  of  their  hard  parts  or 
skeletons  ?  It  is  in  the  nature  of  things  impossible  to  give  a 
direct  answer  to  this  question,  but  the  following  considerations 
suggest  themselves.  As  far  as  our  knowledge  permits  us  to 
pass  beyond  the  region  of  facts,  we  can  but  assume  that  the 
salinity  of  the  sea  is  progressive  or  cumulative,  and  not  the 
reverse,  and  that  the  saline  constituents  of  ocean  water  are 
primarily  the  products  of  destruction  arising  from  the  wear 
and  tear  of  the  land-surface.  There  seems  to  be  no  good  rea- 
son for  supposing  that  the  quantity  of  salts  in  the  sea,  and  of 
lime  especially,  was  ever  much  in  excess  of  what  it  is  to-day, 
unless  it  was  near  the  beginning  of  geological  time ;  on  the  con- 
trary, there  are  some  grounds  for  concluding  that  this  quantity 
may  have  been  less,  and  ev.en  considerably  less.  If  this  con- 
ception is  true,  it  is  manifest  that,  as  far  as  organic  consump- 

*Murray :     "  Structure,  Origin,  and   Distribution  of  Coral  Reefs  and   Islands." 
Nature,  Feb.  28,  1889,  p.  426;  480,000  years  according  to  Reade. 


60  THE  BERMUDA  ISLANDS. 

tion  of  lime  is  concerned,  there  is  either  existing  stability  in 
the  sea,  or  that  the  different  shell-bearing  animals  remove  less 
of  the  formative  material  for  their  own  purposes  than  the  sea 
receives  from  continental  erosion.  In  the  calculation  before 
made  we  have  used  as  a  basis  merely  the  quantity  of  lime-car- 
bonate carried  out  in  solution  by  rivers;  to  this  must  neces- 
sarily be  added  that  which  is  derived  directly  by  the  sea 
through  its  own  breakages — the  wear  of  the  coast-line — and 
the  other  salts  of  lime  of  which  no  account  has  been  taken.  If 
we  double  the  quantity  that  has  been  assumed  we  will  proba- 
bly more  than  cover  the  available  supply ;  a  rate  of  accumula- 
tion, therefore,  of  one  foot  in  50,000  years  would  be  the  result. 
It  is  needless  to  say  that  such  a  slow  accumulation  is  hardly 
compatible  with  any  notion  of  growth  from  great  depths,  and 
that  it  is  entirely  opposed  to  the  view  which  holds  to  the 
formation  of  giant  banks  leading  up  to  the  zone  of  coral  life.* 
But  in  what,  it  might  be  asked,  lies  the  direct  evidence  that 
giant  banks  are  being  built  up  through  organic  accumulations? 
Is  it  merely  the  finding  of  foraminiferal  and  pteropod  ooze  on 
projecting  knobs  of  the  ocean  bottom  ?  This  is  not  a  new  con- 
dition, and  it  is  practically  repeated  in  the  Globigerina  ooze 
which  covers  much  of  the  oceanic  floor.  It  would,  indeed,  be 
remarkable  if  such  deposits  did  not  exist,  but  their  presence 
gives  no  answer  to  the  possibility  of  building  up  giant  banks 
under  the  conditions  which  would  be  considered  necessary  for 
the  making  of  coral  islands.  No  one  has  more  carefully  studied, 
or  is  better  acquainted  with,  the  Florida  reefs  than  Alexander 
Agassiz,  and  perhaps  no  class  of  reefs  has  been  more  frequently 
appealed  to  in  the  recent  discussion  of  coral  structures  than 
those  examined  by  this  authority.  We  are  informed  by  Mr. 
Agassiz  that  these  reefs  are  merely  organic  growths  and  ac- 

*In  evidence  of  the  possible  rapid  accumulation  of  a  foraminiferal  and 
pteropod  deposit,  and  the  building  up  of  submarine  banks,  Prof.  Hickson  (Address  be- 
fore British  Assoc.,  Bath,  1888)  instances  the  case  of  the  basal  limestone  of  the 
elevated  reefs  of  the  Solomon  Islands,  to  which  attention  has  been  called  by  Guppy. 
But  manifestly  this  limestone  was  formed  in  shallow  water,  where  the  conditions  for 
rapid  organic  accumulation  are  almost  infinitely  more  favorable  than  they  are  in  deep 
water. 


THE  CORAL-KEEF  PROBLEM.          61 

cumulations,  whose  present  positions,  whether  of  horizontal  or 
vertical  distribution,  have  practically  no  connection  with  re- 
cent movements  either  of  elevation  or  depression.  "  There  is 
practically  no  evidence  that  the  Florida  reef,  or  any  part  of  the 
southern  peninsula  of  Florida  which  has  been  formed  by  corals, 
owes  its  existence  to  the  effect  of  elevation  ;  or  that  the  atolls  of 
this  district,  such  as  those  of  the  Marquesas  or  of  the  great 
Alacran  Reef,  owe  their  peculiar  structure  to  subsidence."1  On 
what  evidence,  it  might  be  asked,  rest  these  assertions?  It  may 
not  he  easy  to  prove  subsidence  in  the  case  of  the  Marquesas 
and  the  Alacran  Reef,  but  I  believe  it  would  be  equally  diffi- 
cult to  prove  the  reverse  proposition — i.e.,  that  there  has  been  no 
subsidence.  As  far  as  the  Florida  reefs  themselves  are  concerned, 
I  believe  the  evidence  is  aril  but  conclusive  that  they  owe  much, 
if  not  most,  of  their  existence  to  uplift,  and  to  uplift  within  a 
recent  geological  period.  My  own  researches  in  the  southern 
part  of  the  peninsula  have  demonstrated  the  existence  of  Plio- 
cene deposits  in  vast  horizontal,  or  nearly  horizontal,  beds  as  far 
south  as  the  Caloosahatchie,  and  there  can  be  no  question  that 
these  deposits,  which  rise  to  10  or  15  feet  above  the  level  of  the  sea. 
are  continued  for  some  distance  still  further  to  the  south.2  The 
same  deposits,  moreover,  are  capped  by  deposits  of  Post- Pliocene 
age,  proving  that  an  uplift  took  place  in  this  region  as  late  as  the 
Post-Pliocene  period.  That  this  uplift  should  not  have  affected 
the  apex  of  the  peninsula,  and  even  the  reefs  beyond,  seems 
scarcely  credible.  From  what  we  now  know  of  the  structure  of 
the  Floridian  peninsula  it  is  clear  that  this  portion  of  the 
North  American  continent  represents  a  comparatively  old 
chapter  in  geological  history,  and  that  it  has  passed  through 
.much  the  same  phases  of  construction  as  the  border  area  of  the 
Eastern  and  Southern  United  States.  Its  periods  of  elevation 
and  depression,  extending  back  through  the  greater  portion  of 
the  Tertiary  epoch,  were  largely  coincident  with  those  of  the 

l"  Three  Cruises  of  the  Blake."     I,  p.  61 .     1888. 

2"  Explorations  on  the  West  Coast  of  Florida  and  in  the  Okeechobee  Wilder- 
ness," 1887. 


62  THE  BERMUDA  ISLANDS. 

regions  above  indicated,  and  the  movements  were  with  little 
doubt  long  sustained,  and  certainly  affected  large  areas  at  a 
time.  There  is  nothing,  as  far  as  I  can  see,  to  indicate  that 
these  movements  were  confined  to  what  is  now  dry  land ;  the 
more  natural  conclusion  is  that  the  axial  or  plateau  uplift  ex- 
tended much  beyond  the  limits  of  the  present  peninsula,  and 
as  well  southward  as  westward  or  eastward.  The  similarity  in 
the  geological  structure  of  Yucatan,  as  it  appears  from  our  pres- 
ent knowledge,  lends  weight  to  the  supposition  that  the  area 
thus  affected  by  movements  was  perhaps  continuous  completely 
across  the  Gulf. 

In  explanation  of  the  distinctive  form  of  atolls — the  ring 
of  coral  with  its  inclosed  lagoon — it  is  claimed  by  the  oppo- 
nents of  the  subsidence  theory  that  coral  plantations  building 
up  from  submarine  banks  will  grow  more  rapidly  on  their 
outer  margins,  where  the  food  supply  is  the  greatest,  and 
where,  as  compared  with  the  inner  parts  of  the  mass,  there  is 
less  obstructive  sediment,  and  thus  an  exterior  rim  or  eleva- 
tion would  be  formed.  The  differentiation  of  the  inner  and 
outer  parts,  it  is  assumed,  would  be  further  intensified  by  the 
removal  in  solution  of  the  lime-carbonate  from  the  less  active 
interior  portion — the  region  of  coral  decay  and  detrital  accum- 
ulation— and  the  formation  there  of  a  shallow  pan  of  water  or 
lagoon.  That  the  distinctive  features  of  an  atoll  may  be  brought 
about  somewhat  in  the  manner  here  described  can  scarcely 
be  doubted;  indeed,  the  supplemental  atolls  of  diminutive  size 
that  so  frequently  accompany  the  larger  reefs,  the  serpula-reefs 
of  the  Bermudas  for  example,  convincingly  prove  the  possi- 
bility of  ring  structure  without  subsidence.  But  in  instances 
of  this  kind  the  ring  is^  merely  a  narrow  projection,  barely 
rising  above  the  shallow  central  depression,  and  is  due  prob- 
ably more  to  the  action  of  a  beating  surf  than  to  any  other 
cause.  In  the  case  of  a  true  atoll  with  a  large  lagoon  the  con- 
ditions are  very  different,  and  it  seems  impossible  to  explain 
the  central  depression,  often  20,  30,  and  40  fathoms,  or  even 


THE  CORAL-REEF  PROBLEM.          63 

more,  in  depth,  on  the  assumption  of  internal  solution,  aided 
by  external  acceleration  as  dependent  upon  an  increased  food 
supply.  It  does  not  appear  exactly  clear  why  solution  should 
progress  more  rapidly  within  the  lagoon  than  over  the  deeper 
slopes  of  the  coral  buttress,  where  the  protective  power  of  the 
living  animal  is  also  wanting;  nor  is  it  at  all  likely  that  such 
solution  as  actually  does  take  place  within  the  lagoon  more 
than  compensates  for  the  accretion  of  sedimentary  material 
derived  from  the  destruction  of  the  surrounding  shores,  or  for 
the  organic  accumulation  that  is  continuously  forming  along 
the  floor  of  the  lagoon. 

My  examination  of  the  Bermudas  convinces  me  that,  as  far 
as  those  islands  are  concerned,  the  quantity  of  lime  removed 
from  the  interior  waters  is  far  less  than  that  which  is  added 
through  sedimentation  and  organic  development.  The  bot- 
tom is  everywhere  covered  with  fine  debris,  and  the  even  floor 
indicates  that  this  debris  is  of  considerable  thickness.  One 
has  but  to  gaze  upon  the  undercut  and  crumbling  ledges  of 
Harrington  Sound  and  the  cliffs  facing  the  lagoon  to  be  con- 
vinced that  accumulation,  and  not  solution,  is  the  prevailing 
condition  in  these  waters.  Yet  we  have  here  a  depth  of  water 
of  from  50  to  80  feet.  I  am,  indeed,  far  from  convinced  that 
the  organic  accumulation  which  is  here  taking  place  by  actual 
growth  does  not  far  surpass  the  material  removed  through  solu- 
tion. The  tests,  both  perfect  and  fragmentary,  of  Foraminifera 
are  abundant  everywhere,  but  in  addition  to  material  derived 
from  this  source,  there  exist  large  areas  which  are  seemingly 
well  covered  with  the  shells  of  molluscous  animals  (Chama, 
Area,  Avicula,  etc.)  and  sea-urchins  (Toxopneustes  variegatus). 
The  latter,  with  Area  Nose,  are  especially  abundant.  The 
coral  growth  of  Castle  Harbor,  and  not  less  the  insular 
patches  of  millepore,  etc.,  in  the  big  lagoon,  speak  with  suffi- 
cient emphasis  on  this  point.  There  can  be  no  doubt,  too, 
that  some  of  the  basins  and  channels  have  been  recently 
shallowing  through  silting,  but  of  course  this  may  have  been 
brought  about  through  a  mere  transference  of  material  from 


64  THE  BERMUDA  ISLANDS. 

one  point  to  another.  The  depth  of  water  in  the  Flatts  Inlet, 
which  receives  a  strong  tidal  current  from  the  outer  lagoon  and 
from  Harrington  Sound,  is  much  less  to-day  than  it  was  in 
the  early  part  of  the  century,  when  the  Inlet  furnished  a  safe 
anchorage  to  vessels  of  large  draught. 

Mr.  Bourne  finds  similar  conditions  to  exist  in  the  lagoons 
of  the  Diego  Garcia  reef,  and  he  entirely  rejects  the  theory 
that  lagoons  could  have  been  primarily  formed  through  solu- 
tion. He  shows  that  nowhere  has  the  lagoon  deepened  since 
the  time  when  Capt.  Moresby  surveyed  the  region  in  1837,  but, 
on  the  contrary,  evidences  of  shoaling  to  the  extent  of  a  full 
fathom  on  the  south  side  are  not  wanting.  It  is  also  pointed 
out  that  the  depth  of  water  in  the  lagoons  of  the  various 
islands  which  are  associated  with  Diego  Garcia  is  not  propor- 
tional to  the  size  of  the  lagoon,  as  we  should  naturally  expect 
to  find  it  in  accordance  with  the  theory  of  solution.  This  is  also 
true  of  the  Bermudian  waters,  although  their  relations 
somewhat  differ  from  those  of  the  Chagos  Banks.  Thus, 
the  depth  of  water  in  the  comparatively  small  Harrington 
Sound  is  measurably  greater  than  that  of  the  outer  water,  the 
big  lagoon;  it  is  also  much  greater  than  we  find  it  in  the 
superficially  more  extensive  Castle  Harbor. 

Experiments  made  to  determine  the  solvent  power  of  sea- 
water  show  that  the  process  of  solution  is  a  very  slow  one.  It 
appears  indeed  incredible,  in  the  face  of  such  energetic  solu- 
tion as  is  presumed  to  exist  in  the  upper  waters  of  the  ocean, 
that  any  extensive  organic  accumulation  could  ever  take  place 
over  the  floor  of  the  sea,  where  the  solvent  power  of  the  water 
is  materially  increased  through  pressure,  and  still  less  possible 
that  any  considerable  foundation  could  be  built  up  from  it,  or 
irom  the  summit  of  only  a  moderately  depressed  mountain 
peak.  The  fact  that  in  so  large  a  number  of  atolls  the  lagoons 
are  either  entirely  wanting,  or  are  reduced  to  mere  shallow 
pans  of  water,  also  militates  against  the  hypothesis  of  solution. 

With  regard  to  the  formation  of  the  primary  ring  through 
accelerated  growth  oil  the  outer  margin,  as  depending  upon 


BERMUDA   COTTAGE. 


THE  CORAL-REEF  PROBLEM.          65 

an  increased  food-supply,  it  may  be  reasonably  doubted  if  this 
condition  could  obtain  in  the  open  ocean  away  from  a  land 
area,  inasmuch  as  by  far  the  greater  quantity  of  the  food-sup- 
ply would  be  given  to  the  polyps  as  a  direct  down-pouring 
from  above,  and  independently,  or  nearly  so,  of  any  currental 
action.  It  is  true  that  the  outer  polyps  or  colonies  would  be 
favored  by  having  an  extra  supply  on  their  exposed  bor- 
ders, but  this  would  tend  probably  in  the  majority  of  cases 
only  to  lateral  extension,  or  to  lateral  extension  combined 
with  upward  growth — in  other  words,  to  a  simple  turbinated 
growth  with  a  nearly  flat  top.  It  is  true  that  in  a  few  instances, 
as  has  been  noted  by  Semper  and  Darwin,  colonies  of  Porites, 
having  a  turbinated  form,  exhibit  a  raised  border  or  lip,  but  it 
is  equally  true  that  in  by  far  the  greater  number  of  cases  the 
individual  larger  colonies  assume  either  a  clavate  or  a  hemi- 
spherical form,  the  latter  condition  being  also  distinctive  of 
the  giant  brain-corals.  Mr.  Bourne,  from  his  researches  on 
the  Diego  Garcia  reef,  also  dismisses  the  notion  that  food-con- 
veying currents  are  especially  instrumental  in  shaping  the 
reefs,  and  he  points  out  that  frequently  the  most  elevated  side 
of  an  atoll  is  turned  away  from  such  currents,  and,  again,  that 
a  large  number  of  coral  islands  are  placed  entirely  to  one  side, 
or  out  of  the  path,  of  the  prevailing  ocean  current. 

But  even  granting  that  through  some  method  of  accelerated 
growth  on  the  exterior  an  elevated  bounding  ring  sho-ild  be 
formed,  the  difficulty  in  accounting  for  the  existence  of  the 
deep  lagoon  would  in  no  wise  be  lessened  ;  for,  in  the  first 
place,  no  such  ring  would  be  formed  below  the  line  of  coral 
growth,  and  we  should  consequently  be  compelled  to  assume 
as  antecedent  to  its  formation  the  complete  upward  growth  or 
elevation  of  the  submerged  bank  to  the  true  coral  zone,  or  to 
a  greatest  possible  depth  beneath  the  surface  of  100  or  120 
feet.  Manifestly,  under  such  conditions  there  could  be  no 
deep  depression  corresponding  to  lagoons  of  200  or  300  feet 
depth,  unless  these  were  subsequently  formed  by  means  other 
than  solution.  Furthermore,  it  appears  that  the  true  energy 


66  THE  BERMUDA  ISLANDS. 

of  coral  growth  is  concentrated  in  the  first  zone  of  some  fifty 
or  sixty  feet,  which  would  practically  mark  the  depth  at  which 
a  bounding  rim  of  accelerated  growth  would  be  formed,  and 
also  fix  the  depth  of  the  lagoons.*  But  as  has  already  been 
seen,  the  depth  of  nearly  all  extensive  lagoons  is  very  much 
greater,  in  some  cases  six  times  as  great,  or  more. 

The  difficulty  in  the  premises  disappears  almost  entirely  if 
we  accept  Mr.  Darwin's  hypothesis  of  subsidence,  for  here  the 
accelerated  outer  growth  is  assumed  to  depend  no  less  upon 
interior  retardation  (as  the  result  of  the  accumulation  of  in- 
jurious sediment),  as  upon  an  actual  increase  in  the  quantity 
of  the  food-supply.  The  depth  and  size  of  the  lagoon  will 
then  depend  upon  the  extent  of  land  that  has  undergone  sub- 
sidence, and  upon  the  measure  of  its  submergence.  Where 
the  descent  is  very  gradual  the  upward  development  of  the 
coral  structures  may  by  overgrowth  completely  close  out  the 
lagoon ;  where,  on  the  other  hand,  the  descent  is  unusually  rapid, 
more  rapid  than  the  compensating  upward  growth  of  the  corals, 
a  "  drowned  "  atoll  may  be  the  result.  The  great  Chagos  Bank, 
which  is  situated  some  700  miles  to  the  south  of  the  Maldives 
and  has  a  length  of  about  90  miles  with  a  greatest  width  of 
70  miles,  has  generally  been  assumed  to  be  only  a  completely 
submerged  or  drowned  atoll.  If  raised  to  the  surface  it  would 
be  in  the  form  of  a  true  atoll,  with  a  depth  of  water  in  the 
lagoon  of  40-50  fathoms.  At  the  present  time  the  bounding 
reef  is  covered  with  water  of  from  4  to  10  fathoms  depth.  The 
Bermuda  Islands  have  also  been  instanced  as  an  example  of  a 
partially  drowned  atoll,  but,  as  has  been  shown  in  the  preced- 

*It  is  surprising  that  this  consideration  in  the  assumed  formation  of  deep  lagoons 
through  accelerated  marginal  growth  should  be  so  generally  overlooked.  Prof.  Hick- 
son,  in  his  address  before  the  British  Association  (1888)  on  "  Theories  of  Coral  Reefs 
and  Atolls,"  furnishes  an  instance  of  such  oversight.  He  says :  "  It  seems  very 
probable  then  that  when  a  large  submarine  bank,  by  accumulation  of  sediment  or  by 
elevation,  comes  within  the  limit  of  coral  growth,  the  growth  commences  and  is 
almost  confined  to  the  edges  of  the  bank,  and  that  in  course  of  time  the  edges  of  the 
bank  reach  the  surface,  whilst  the  centre  of  the  bank  has  made  little  or  no  progress. 
This  seems  to  be  a  very  reasonable  explanation  of  the  deep  lagoons  of  large  atolls, 
and  one  to  which  at  present  I  can  see  no  valid  objection." 


THE  CORAL-REEF  PROBLEM.  67 

/ 

ing  chapter,  there  is  nothing  in  the  present  land-mass  to  indi- 
cate that  it  bears  any  direct  relation  to  an  atoll  ring. 

An  objection  that  has  been  frequently  urged  against  the  sub- 
sidence theory,  and  one  that  has  been  more  particularly  in- 
sisted upon  by  Guppy  as  the  result  of  extended  observations 
made  in  the  Solomon  Islands,  is  that  where  fringing  reefs  are 
exposed  they  usually  exhibit  only  a  moderate  thickness  of 
true  coral-rock,  the  basement  or  sub-structure  being  mainly  of 
a  pelagic  character — that  is,  built  up  of  the  remains  of 
pelagic  animals  (Foraminifera,  etc).  Hence,  it  is  argued  that 
in  the  so-called  subsidence  reefs — atolls  and  barrier-reefs, — the 
actual  thickness  of  coral  is  very  limited,  or  barely  more  than 
that  which  would  fall  within  the  regular  zone  of  coral  growth. 
The  few  observations  that  have  been  made  on  this  point,  can- 
not be  considered  to  throw  much  light  upon  the  question,  the 
more  especially  as  the  evidence  obtained  is  far  from  corrobora- 
tive. Furthermore,  it  is  just  in  such  elevated  reefs  that  in  ac- 
cordance with  the  Darwinian  theory  we  should  frequently 
look  for  a  thin  deposit  of  coral-rock,  for  if  there  has  been  eleva- 
tion instead  of  subsidence  the  thickness  must  necessarily  be 
slight;  when,  however,  subsidence  had  preceded  elevation  the 
result  would  be  the  opposite.  No  weight  should  be  attached  to 
the  oft-repeated  assertion  that  in  the  older  geological  forma- 
tions there  are  no  really  massive  reef-structures.  This  asser- 
tion is  entirely  opposed  to  the  facts,  to  cite  but  a  single  instance 
presented  by  the  Dolomites  of  the  Tyrol,  the  reef-structure  of 
which  has  been  so  ably  worked  out  by  Mojsisovics  and  others. 
Furthermore,  it  is  practically  impossible  in  the  case  of  a  large 
number  of  the  altered  limestones  to  state  whether  they  are  of 
coral  origin  or  not. 

One  objection  against  the  subsidence  theory  has  still  to  be 
considered.  It  is  the  association  of  fringing  reefs  with  atolls. 
This  commingling  of  two  distinct  types  of  structure,  implying 
movements  in  opposite  directions,  has  been  much  commented 
upon,  and  placed  under  strong  emphasis  by  the  adherents  of 
the  new  views  regarding  the  formation  of  coral  islands.  But 
the  occurrence  appears  to  be  entirely  without  significance. 


68  THE  BERMUDA  ISLANDS. 

An  alternate  movement  of  elevation  and  subsidence  is  no 
more  strange  over  an  oceanic  area  than  it  is  on  the  continental 
borders.  Yet  we  have  here  almost  everywhere  evidences  of  a 
differential  movement,  and  no  geologist  has  for  a  moment  ex- 
pressed surprise  at  the  manifestation.  What  then  is  the 
anomaly  of  the  occurrence  of  such  movements  in  a  coralline  sea  ? 
How  is  the  conception  of  subsidence  antagonized  by  the  facts 
of  elevation?  If  we  conceive  of  an  atoll,  with  a  deep  lagoon, 
once  having  been  formed  through  subsidence,  what  is  to  pre- 
vent a  succeeding  elevation  from  lifting  parts  of  this  atoll,  or 
for  that  matter,  the  entire  atoll-ring,  above  the  water?  We 
could  still  have  the  lagoon  of  subsidence  retained,  and  yet  as  a 
last  record  of  movement  we  would  have  merely  the  evidence 
of  elevation.  Because  a  certain  structure  is  formed  through 
subsidence  it  does  not  follow  that  this  subsidence  should  not 
be  followed  by  elevajbion.  This  is  but  the  order  of  things  we 
find  everywhere  expressed  in  the  history  of  continental  masses. 
Indeed  it  would  be  but  natural  to  look  for  local  oscillations  in 
regions  of  extensive  movement.  Mr.  Bourne  lays  great  stress 
upon  the  evidences  of  elevation  (of  a  few  feet)  which  are  pre- 
sented by  Diego  Garcia,  and  claims  them  to  be  conclusive 
against  "the  idea  of  any  subsidence  being  in  progress,  as  Mr. 
Darwin  fancied  to  be  the  case  in  the  Keeling  atoll  "*.  I  con- 
fess that  I  can  find  nothing  in  this  evidence  which  would  pre- 
clude an  assumption  of  subsidence  sufficiently  recent  to  have 
produced  the  characteristic  atoll  form.  We  have  in  the  elevated 
beach-rock  of  the  Bermudas  unequivocal  evidences  of  elevation, 
but  equally  conclusive  are  the  evidences  of  the  subsidence 
which  followed  this  elevation.  In  other  words  we  have  here 
the  conditions  of  Diego  Garcia  simply  reversed.  Again,  in  re- 
gions where,  as  in  that  represented  by  the  great  Chagos  Bank, 
it  might  be  assumed  that  "  drowned  "  atolls  have  been  formed 
as  the  result  of  too  rapid  subsidence,  a  change  of  movement 
would  be  all  but  certain  to  develop  reefs  of  elevation  in  combi- 
nation with  those  which  are  assumed  to  bear  in  their  structure 

*Loe.  «'/.,  p.  446. 


THE  CORAL-REEF  PROBLEM.          69 

the  evidences  of  subsidence.  In  other  words,  there  would  be  an 
interassociation  in  the  same  archipelago  of  both  fringing  reefs 
and  atolls,  for  it  can  scarcely  be  conceived  that  all  the  project- 
ing land-masses  of  the  archipelago  could,  at  the  time  when 
movements  of  one  kind  or  another  set  in,  have  been  equally 
elevated  above,  or  depressed  beneath,  the  surface  of  the  water. 
Hence,  unequal  developments  must  have  taken  place. 

Such  are  the  principal  circumstances  connected  with  the 
history  of  coral  islands.  If  the  theory  of  subsidence  cannot, 
perhaps,  be  considered  to  be  absolutely  demonstrated,  it  ac- 
cords best  with  the  facts,  and,  indeed,  may  be  said  to  be  in 
substantial  harmony  with  them.  Furthermore,  it  helps  to  ex- 
plain the  significant  fact,  first  pointed  out  by  Dana,  that  a 
very  large,  if  not  the  greater,  number  of  coral  structures  ure 
ranged  along  the  line  of  greatest  depression  in  the  sea. 

The  question  here  naturally  suggests  itself:  Is  there  any 
evidence  supporting  the  theory  of  assumed  subsidence  of  the 
oceanic  basins  beyond  what  is  furnished  by  the  coral  islands? 
It  must  be  admitted  that  our  positive  knowledge  on  this 
point  is  very  limited — indeed,  almost  nothing.  But  various 
considerations  lead  to  the  belief  that  the  present  site  of  the 
oceanic  basins  is  a  very  ancient  one,  and  possibly  one  that  has 
not  materially  changed,  except  in  so  far  as  intensification  is 
concerned,  since  it  was  first  marked  out  as  the  most  prominent 
feature  of  the  earth's  crust.  While  manifestly  we  can  have  no 
proof  of  this  condition,  it  seems  but  reasonable  to  assume  that 
if  this  vast  depression  was  formed  through  an  early  flexure  of 
the  crust,  and  as  the  result  of  weakness  in  certain  parts  of  that 
crust,  it  has  retained  its  position  of  depression  from  the  first. 
With  a  contracting  or  moving  crust,  moreover,  particularly 
under  the  special  conditions  of  loading  (sedimentation)  and 
continental  unloading  (denudation),  it  is  likely  that  a  depres- 
sion of  this  kind  would  tend  to  sink  or  to  subside,  and  force  a 
relief  from  strain  in  the  uplift  of  the  continents.  This  is  the 
view  now  held  by  probably  the  greater  number  of  physicists 


70  THE  BERMUDA  ISLANDS. 

and  geologists.  But  it  does  not  carry  with  it  the  assumption 
of  a  necessary  permanence  in  the  positions  of  continents  and 
oceans;  it  does  not  imply  that  the  oceanic  basins  were 
originally  of  the  extent  that  they  are  to-day,  as  we  are  led  to 
believe  by  many  geologists.  It  is  far  more  probable  that  the 
existing  dimensions  have  been  brought  about  through  pro- 
gressive or  cumulative  subsidence,  which  has  gradually  swept 
away  land-masses  that  at  one  time  occupied  some  of  the  pres- 
ent area  of  the  sea.  The  long  lines  of  ridges  which  have  been 
revealed  to  us  by  deep-sea  soundings,  and  the  placing  on  these 
of  many  of  the  oceanic  islands  (volcanic  peaks),  together  with 
the  evidence  which  the  past  and  present  distribution  of  animal 
life  carries  with  it,  all  support  this  conclusion.  It  seems,  in- 
deed, impossible  to  account  for  the  existence  of  oceanic  (vol- 
canic) islands,  or  for  the  negative  islands  which  rise  as  promi- 
nences from  the  oceanic  floor  to  within  a  comparatively  short 
distance  of  the  surface,  except  on  the  assumption  of  subsidence. 
What  is  the  significance  of  buttresses  like  St.  Helena,  Ascen- 
sion, the  Caroline  Islands,  or  the  giant  peaks  of  the  Sandwich 
Islands  rising  from  depths  of  two  or  three  miles,  or  more? 
Can  it  be  assumed  that  they  have  been  steadily  built  up  vol- 
canically  from  the  ocean  floor,  four  or  five  miles  in  height? 
This  is,  perhaps,  not  impossible,  but  it  hardly  appears  prob- 
able. Vulcanisin  in  one  form  or  another  doubtless  manifests 
itself  over  the  floor  of  the  ocean,  but  all  indications  point  to  a 
comparatively  limited  action  in  the  greater  depths.  Were 
submarine  eruptions  at  all  numerous,  or  of  that  intensity 
which  might  be  assumed  to  be  necessary  for  the  construction 
of  a  giant  mountain-peak,  we  should  be  probably  made 
aware  of  their  existence  in  a  manner  not  less  emphatic  than 
in  the  case  of  subaerial  eruptions.  It  might  be  assumed  that 
the  long  intervals  at  which  eruptions  take  place  would  prevent 
special  notice  of  such  phenomena,  and  that,  consequently, 
their  effects,  even  if  most  momentous,  would  be  placed  prac- 
tically beyond  observation.  But  this  is  not  likely  to  be  the 
case.  When  we  consider  the  large  number  of  peaks  that  in 


THE  CORAL-REEF  PROBLEM.          71 

one  form  or  another  come  to,  or  beyond,  the  surface,  and  real- 
ize how  few  of  them  are  in  a  condition  of  activity,  it  is  diffi- 
cult to  believe  that  many  of  these  peaks  are  to-day  in  a  course 
of  volcanic  construction,  or  that  other  submarine  peaks,  scat- 
tered between  these,  are  undergoing  a  similar  process  of  for- 
mation. It  seems  far  more  natural  to  assume  that  these  peaks 
or  islands  have  been  for  a  long  time  fully  formed,  and  that 
they  were  formed  at  a  time  when  their  relations  to  the  sur- 
rounding sea  were  more  nearly  those  which  govern  the  posi- 
tions of  by  far  the  greater  number  of  the  active  volcanoes  of 
to-day.  In  other  words,  they  were  probably  continental  or 
sub-continental,  and  their  present  positions  are  the  indices  of 
continental  subsidence;  the  vast  mass  of  overflowing  water 
may  have  extinguished  the  fires  that  at  one  time  supplied  the 
material  for  eruption. 

The  recent  discovery  of  a  large  number  of  submarine  peaks, 
whose  existence  had  not  previously  been  even  surmised,  rising 
to  within  a  comparatively  short  distance  of  the  surface,  seems 
to  support  the  general  conclusion  of  subsidence.  The  sound- 
ings of  telegraph  ships  indicate  that  between  the  latitude  of 
Lisbon  and  the  island  of  Teneriffe  there  are  not  less  than  seven 
peaks  over  which  the  depth  of  water  varies  from  not  more  than 
12  to  500  fathoms.  From  the  entire  oceanic  basin  it  is  claimed 
that  there  are  already  known  about  300  such  "submarine 
cones,  rising  from  great  depths  up  to  within  depths  of  from  500 
to  10  fathoms  from  the  surface  "*. 

Probably  the  greatest  difficulty  that  lies  in  the  way  of  the 
acceptance  of  the  subsidence  theory  of  coral  structures  is  the 
fact  that  there  are  not  more  islands  which  are  in  a  condition 
of  semi-formation — i.  e.,  peaks,  partially  submerged  and  sur- 
rounded by  an  encircling  barrier  reef.  This  is  not  an  in- 
superable objection,  and  might  be  treated  by  some  geologists 
in  the  nature  of  negative  evidence.  But  the  fact  is  of  signifi- 
cance, and  must  be  taken  into  account  for  whatever  it  may  be 

*Murray  :  Nature,  Feb.  28,  1889,  p.  425, 


72  THE  BERMUDA  ISLANDS. 

worth,  in  all   theories  bearing  upon   the  formation  of  coral 
islands. 

Since  the  preceding  notes  were  sent  to  press  Alexander 
Agassiz  has  published  his  observations  on  the  "  Coral  Reefs  of 
the  Hawaiian  Islands."*  This  paper,  apart  from  giving  de- 
tailed descriptions  of  the  reefs  of  the  Sandwich  Islands, 
presents,  on  the  whole,  perhaps  the  clearest  statement  of  views 
bearing  upon  the  structure  of  coral  islands  that  has  yet  been 
published,  but  it  can  scarcely  be  said  that  it  contributes 
materially  toward  the  solution  of  the  general  problem.  Mr. 
Agassiz  asserts  himself  to  be  a  pronounced  opponent  of  the 
theory  of  subsidence,  as,  indeed,  he  has  always  been  since  he 
first  undertook  the  very  careful  survey  of  the  Florida  reefs. 
I  think  it  will  be  generally  admitted,  however,  that  the  evi- 
dence which  is  now  brought  forward  is,  as  far  as  the  substitute 
theory  is  concerned,  almost  wholly  negative,  while  much  of  it 
favors  the  theory  of  subsidence.  Mr.  Agassiz  assumes  certain 
definite  premises  or  propositions,  which  are  dogmatically 
stated,  but  it  is  difficult  to  find  the  exact  evidence  upon  which 
these  premises  are  based.  The  special  points  of  evidence 
which,  in  the  opinion  of  this  authority,  render  the  subsidence 
theory  unnecessary  and  untenable  are  practically  the  same  as 
those  which  have  already  been  discussed,  and  consequently 
they  call  for  but  little  detailed  consideration. 

Mr.  Agassiz  considers  it  "remarkable  that  Darwin,  who  is  so 
strongly  opposed  to  all  cataclysmic  explanations,  should  in 
the  case  of  the  coral  reefs  cling  to  a  theory  which  is  based 
upon  the  disappearance  of  a  Pacific  continent,  and  be  appar- 
ently so  unwilling  to  recognize  the  agency  of  more  natural 
and  far  simpler  causes ; "  and  he  further  expresses  himself : 
"  as  long  as  we  can  in  so  many  districts  explain  the  formation 
of  atolls  and  of  barrier  reefs  by  other  causes,  fully  sufficient  to 
account  for  the  numerous  exceptions  to  the  theory  of  Darwin, 
which  have  been  observed  by  so  many  investigators  since  the 

^Bulletin  Mus.  Comp.  Zoology,  XVII,  April,  1889. 


THE  CORAL-REEF  PROBLEM.         73 

days  of  Darwin  and  Dana,  it  seems  unnecessary  to  account  for 
their  presence  by  a  gigantic  subsidence,  of  which  although  we 
may  not  deny  it,  we  can  yet  have  but  little  positive  proof" 
(p.  131).  These  reflections  are  well  so  far  as  they  go,  but  have 
the  "  natural  and  far  simpler  causes  "  underlying  the  forma- 
tion of  coral  reefs,  which  are  to  take  precedence  over  the  Dar- 
winian hypothesis,  been  satisfactorily  demonstrated  ?  I  believe 
not,  and  I  further  believe  with  Dana  and  Von  Lendenfeld  that 
no  facts  that  have  yet  been  brought  forward  stand  in  direct  op- 
p«  sition  to  the  theory  of  subsidence.*  Mr.  Agassiz  assures  us 
that  the  "  Mosquito  Bank,  the  Yucatan  Bank,  and  the  smaller 
banks  between  Honduras  and  Jamaica,  are  all  proof  that 
limestone  banks  are  forming  at  any  depth  in  the  sea,  or  upon 
pre-existing  telluric  folds  or  peaks,  constituting  banks  upon 
which,  when  they  have  reached  a  certain  depth,  corals  will 
grow  "  (p.  133),  and  a  similar  condition  is  considered  to  under- 
lie the  formation  of  the  Florida  reefs.  It  has,  however,  not 
been  shown  that  these  banks  have  been  actually  built  up  in 
the  manner  that  has  been  described,  or  that  any  other  banks 
have  been  similarly  reared  from  really  great  depths.  The 
assertion  that  the  Florida  reefs  have  not  been  assisted  in  their 
upward  growth  by  elevation  (p.  142)  is,  as  far  as  I  can  see,  not 
supported  by  fact,  for  we  have  in  the  regular  horizontal  lime- 
stone beds  of  the  southern  part  of  the  peninsula  the  most  con- 
clusive evidence  of  elevation  even  as  late  as  the  Pliocene  and 
Post-Pliocene  periods,  and  there  is  every  reason  to  believe, 
even  if  the  condition  cannot  be  proved,  that  this  upward 
movement  did  not  stop  short  of  the  coral-forming  tract.  Nor 
does  this  movement  of  elevation  preclude  the  possibility  of 
subsidences  having  taken  place  coincidentally  in  the  same  re- 
gion. It  appears  to  me  by  no  means  certain  that  the  deep 
channel  now  separating  the  apex  of  the  peninsula  of  Florida 
from  Cuba,  and  known  as  the  Straits  of  Florida,  was  really 
cut  by  the  Gulf  Stream,  as  is  maintained  by  Mr.  Agassiz.  It 
seems  to  me  far  more  probable  that  it,  as  well  as  some  of  the 

*Natu)rvissens(ft<iftliche  A'utu/sc/iatt,  Oct.  13,  1888. 


74  THE  BERMUDA  ISLANDS. 

other  deep  channels  separating  the  West  Indian  Islands,  was 
formed  through  subsidence — the  result  of  localized  breakages 
in  the  crust.  This  view  has  already  been  expressed  by  Suess,1 
who  draws  a  close  parallel  between  the  physiographic  con- 
struction of  the  basin  of  the  Gulf  of  Mexico  and  that  of  the 
Mediterranean. 

Mr.  Agassiz  thinks  it  "  somewhat  surprising  that,  in  the  dis- 
cussion which  has  lately  been  carried  on  in  the  English  re- 
views by  the  Duke  of  Argyll,  Huxley,  Judd,  and  others, 
regarding  the  new  theory  of  coral  reefs,  no  one  should  have 
dwelt  upon  the  fact,  that,  with  the  exception  of  Dana,  Jukes, 
and  others  who  published  their  results  on  coral  reefs  soon 
after  Darwin's  theory  took  the  scientific  world  by  storm,  not  a 
single  recent  original  investigator  of  coral  reefs  has  been  able 
to  accept  this  explanation  as  applicable  to  the  special  district 
which  he  himself  examined  "  (p.  133).  This  condition  may  be 
surprising,  but  it  is  not  less  surprising  that  the  different  in- 
vestigators who  have  rejected  the  Darwinian  hypothesis  should 
have  thus  far  failed  to  agree  among  themselves  as  to  their  own 
special  theories.  Thus,  the  "  solution  theory  "  of  the  formation 
of  the  atoll-lagoon,  which  has  been  so  much  emphasized  by 
Mr.  Murray,  and  the  possibilities  of  which  we  have  already 
discussed,  is  practicably  rejected  by  Bourne,  Guppy,  and 
Wharton2,  and  even  Agassiz  expresses  himself  not  fully  satis- 
fied with  its  efficiency.  And  as  far  as  I  know  no  satisfactory 
explanation  of  the  formation  of  the  deep'  lagoons  has  been 
given  by  any  of  these  investigators.  Captain  Warton  has  re- 
cently described3  a  number  of  submerged  reef-structures  in 
the  China  Sea  which  have  a  deep  flat  centre,  surrounded  by 
an  elevated  growing  rim ;  it  is  assumed  that  were  this  rim  to 
grow  up  to  the  surface  we  would  have  the  characteristic  feat- 
ures of  an  atoll,  with  its  deep  central  lagoon,  presented.  But 

^•Antlilz  der  Erde,  I. 

,  Feb.  23, 18*8. 
.  dt.,  p.  393. 


THE  CORAL-REEF  PROBLEM.  75 

there  is  no  evidence  to  show  that  these  submerged  atoll-like 
banks  are  not  really  banks  of  subsidence,  rather  than  of  up- 
Avard  growth,  and  in  their  general  features  they  do  not  differ 
from  the  Chagos  Bank  which  Mr.  Darwin  considered  to  repre- 
sent a  half-drowned  atoll.  Until  a  satisfactory  explanation  is 
furnished  of  the  origin  of  these  central  lagoons,  so  long  must 
any  theory  bearing  upon  the  formation  of  coral  structures  be 
considered  merely  tentative.  In  the  case  of  the  Bermuda 
Islands,  which  limit  the  field  of  my  own  investigations  in  this 
direction,  I  am  confident  that,  whatever  may  have  been  the 
original  construction  of  the  region,  the  present  lagoon  features 
have  been  brought  about  through  subsidence ;  and  this  con- 
clusion was  reached  before  me  by  Prof.  Rice,  who  seems  to 
have  been  amply  satisfied  with  the  subsidence  theory ! 

On  one  point  in  connection  with  his  recent  survey  Mr. 
Agassiz  furnishes  important  testimony,  and  that  is  as  to  the 
actual  thickness  of  the  coral-made  rock,  or,  at  least,  the  depth 
beneath  the  surface  at  which  this  rock  occurs.  This  has  been 
determined  by  the  artesian  borings  made  in  the  vicinity  of 
Honolulu,  and  elsewhere.  At  various  points  the  bore  pierced 
coral-rock  at  depths  of  100-500  feet  beneath  the  sea-level.  In  the 
well  of  Mr.  James  Campbell,  near  the  Pearl  River  Lagoon  (?), 
28  feet  of  white  coral  was  struck  at  a  depth  of  nearly  1000  feet 
below  high-water  mark  (p.  153),  and  again  at  "  Waimea,  Oahu, 
900  feet  was  drilled  through  hard  ringing  coral  rock  "  (p.  152). 
In  these  facts,  however,  Mr.  Agassiz  sees  no  evidence  of  sub- 
sidence. He  prefers  to  account  for  the  great  thickness  of  the 
coral  rock  "  by  the  extension  seaward  of  a  growing  reef,  active 
only  within  narrow  limits  near  the  surface,  which  is  constantly 
pushing  its  way  seaward  upon  the  talus  formed  below  the  liv- 
ing edge.  This  talus  may  be  of  any  thickness,  and  the  older 
the  reef,  the  greater  its  height  would  be,  as  nothing  indicates 
that  in  the  Hawaiian  district  there  has  been  any  subsidence  to 
account  for  such  a  thickness  of  coral  rock  in  its  fringing  reef", 
(p.  154).  But  where  are  the  evidences  which  support  this  ex- 
planation ?  I  must  confess  that  I  fail  to  see  any.  The  assump- 


76  THE  BERMUDA  ISLANDS. 

tion  of  a  seawardly-extending  talus  of  coral  is,  it  appears  to 
me,  purely  gratuitous.  Indeed,  with  the  very  gentle  slope  that 
these  islands  have  beneath  the  sea  it  is  extremely  doubtful  if 
any  extensive  talus  could  accumulate  as  a  result  of  either 
downflow  or  downwash.  Prof.  Dana  has  well  supplied  the 
argument  on  this  point,  and  its  seems  to  me  that  it  is  unan- 
swerable. With  a  gradient  of  perhaps  eight  degrees,  and 
not  impossibly  much  less,  it  is  almost  inconceivable  that  there 
should  be  much  lateral  spread  of  detached  coral  boulders. 
Neither  wave-action  nor  the  action  of  the  oceanic  currents, 
except  possibly  under  conditions  of  earthquake  disturbance, 
would  be  likely  to  effect  the  required  displacement. 

Again,  it  might  be  asked,  what  kind  of  direct  evidence  must 
we  look  for  to  establish  the  point  that  there  has  been  no  great 
progressive  subsidence  in  the  Hawaiian  Islands?  The  needed 
evidence  is  just  of  that  kind  which  it  pleases  the  Earth  to  keep 
to  herself,  and  after  which  the  geologist  has  in  most  instances 
sought  in  vain.  The  fact  that  cinder-cones  are  found  "  with 
their  base  close  to  the  present  sea-level "  proves,  it  appears  to 
me,  nothing  in  this  connection,  and  I  fail  to  see  the  argument 
which  draws  from  their  existence  a  proof  of  non-subsidence. 
But  Agassiz  himself  admits  that  there  is  "some  evidence  of 
subsidence  [about  50  feet]  on  the  southern  shore  of  Hawaii" 
(P-  154). 

On  the  whole,  it  seems  to  me,  that  the  facts  as  they  are  pre- 
sented are,  if  they  indicate  anything  at  all,  directly  in  favor 
of  subsidence,  and  of  subsidence  on  an  extensive  scale.  They 
are  in  my  mind  far  more  conclusive  than  the  somewhat  simi- 
lar facts  which  have  been  generally  accepted  by  geologists  to 
prove  depression  or  subsidence  in  delta-deposits,  such  as  those 
of  the  Mississippi  or  Ganges.  Dr.  W.  O.  Crosby,  in  his  paper 
on  "The  Elevated  Coral  Reefs  of  Cuba,"*  shows  that  the  coral 
limestone  of  Cuba  is  in  places  at  least  a  thousand  feet  in 
'thickness,  and  he  naturally  infers  that  there  must  have  been 

*Proc.  Boston  Soc.  Nat.  History,  XXII,  1882-83,  p.  124. 


THE  CORAL-REEF  PROBLEM.  77 

subsidence  to  nearly  this  amount.  Mr.  Agassiz,  commenting 
on  this  important  observation,  says  (p.  150,  note)  that  it  does 
"  not  throw  any  additional  light  on  Darwin's  theory  of  sub- 
sidence ;  it  is  of  the  same  character  as  all  the  statements 
which  prove  the  subsidence  by  the  existence  of  coral  reefs,  and 
while  there  may  have  been  coral  reefs  formed  during  sub- 
sidence, it  does  not  prove  that  their  growth  is  due  to  subsidence 
any  more  than  the  presence  of  elevated  reefs  proves  them  to 
be  due  to  elevation."  This  criticism  is  in  a  measure  valid? 
but  it  must  be  remembered  that  one  of  the  "  strong  "  points 
urged  by  Guppy  and  others  against  the  subsidence  theory  was 
the  (supposed)  non-existence  of  massive  deposits  of  coral-lime- 
stone, or  such  as  indicated  formation  through  protracted  sub- 
sidence. But  here  we  surely  have  such  a  limestone  (provided 
the  observation  is  correctly  made),  and  its  presence  removes 
what  might  have  been  a  valid  argument  against  the  Darwin- 
ian hypothesis.  And  further,  there  is  reason  to  believe  that 
the  thousands  of  feet  of  reef-structure  which  have  been  do- 
scribed  by  Sawkins  in  Jamaica  are  largely,  if  not  mainly,  of 
coral  growth,  and  represent  a  formation  produced  during  a 
long  period  of  subsidence. 

In  the  foregoing  discussion  of  the  structure  of  coral  reefs,  as 
also  in  the  chapter  treating  of  the  physical  history  of  the  Ber- 
mudas, I  have  used  the  term  "subsidence"  (and  necessarily  its 
opposite — elevation)  in  a  relative  sense,  indicating  a  depression 
or  submergence  of  the  land  beneath  the  sea.  But  whether 
this  submergence  was  due  to  a  positive  movement  on  the  part 
of  the  land,  or  to  a  change  of  level  (rise)  in  the  water,  cannot 
readily  be  determined,  as  the  phenomena  attending  either 
form  of  movement  would  be  practically  identical.  The  broad 
problem  of  oceanic  transgression  and  continental  stability, 
which  has  been  so  forcibly  outlined  by  Suess,  cannot  be 
properly  treated  in  this  place. 


V. 
THE  RELATIONSHIP  OF  THE  BERMUDIAN  FAUNA, 


Mr.  Wallace,  in  "  Island  Life,"  has  ably  discussed  the  more 
general  features  of  the  Bermudian  fauna,  and  analyzed  the- 
conditions  which  gave  to  the  fauna  its  distinctive  characters. 
The  new  material  which  we  were  fortunate  to  obtain  enables 
us  to  enter  further  into  the  discussion,  and  to  supplement  and 
expand  the  conclusions  which  had  been  reached  from  the 
study  of  only  a  limited  number  of  animal  groups. 

In  its  broader  aspects  the  Bermudian  fauna  is  strictly  non- 
continental  ;  it  lacks  those  elements  which  we  associate  with 
the  animal  life  of  any  extended  land  area,  while  negatively,  in 
the  paucity  of  animal  forms  in  general,  it  presents  a  character- 
istic of  insular  faunas.  The  deficiencies  in  both  the  higher  and 
the  lower  groups  of  animals  are  well  marked,  and  the  number 
of  special  types  represented  is  not  very  great.  The  vast  body  of 
water  which  separates  these  islands  from  the  mainland  has,  as 
might  have  been  anticipated,  largely  prevented  the  crossing  of 
American  animals,  and  this  is  true  of  all  the  groups  except 
volants.  Barring  the  two  species  of  whale — right-whale  and 
sperm-whale — which  visit  the  waters  of  the  archipelago,  the 
only  "wild"  mammalian  forms  of  the  region  are  bats,  rats, 
and  a  possible  shrew  (Sorex).  The  animal  supposed  to  be  a 
shrew  is  referred  to  by  Matthew  Jones  (Mammals  of  Bermuda, 
Bull.  U.  S.  National  Museum,  1884),  but  unfortunately  no 
positive  identification  has  been  made.  Four  species  of  rat — 
the  brown  or  Norway  rat,  the  black  rat,  the  tree  or  roof  rat 
(Mas  tedorum),  and  the  common  mouse  (Mus  musculus) — are  re- 


RELATIONSHIP  OF  THE  FAUNA.  79 

corded;  the  black  rat,  as  elsewhere,  is  rapidly  disappearing, 
and  is  now  on  the  verge  of  extinction.  There  is  little  reason 
to  doubt  that  some,  and  possibly  all,  of  these  forms  were  trans- 
ported to  the  islands  in  the  holds  of  vessels,  just  as  they  have 
been  carried  from  Europe  to  America,  but  no  absolute  date  can 
be  fixed  for  the  first  rat  visitation.  If  the  accounts  of  Jourdan 
are  to  be  credited,  no  rats  were  known  prior  to  about  1610, 
although  only  a  few  years  later  (1618)  the  islands  appear  to 
have  been  largely  overrun  by  the  tree-rat,  and  to  such  an  ex- 
tent that,  as  Captain  John  Smith,  in  his  History  of  Virginia, 
says,  "  there  was  no  island  but  it  was  pestered  with  them  ;  and 
some  fishes  have  been  taken  with  rats  in  their  bellies,  which 
they  caught  in  swimming  from  ile  to  ile;  their  nests  had 
almost  in  every  tree,  and  in  most  places  their  burrowes  in  the 
ground  like  conies;  they  spared  not  the  fruits  of  the  plants,  or 
trees,  nor  the  very  plants  themselves,  but  ate  them  up"  (Jones, 
p.  158).  This  great  abundance,  as  Matthew  Jones  well  remarks, 
points  to  a  much  earlier  colonization  than  the  purely  historical 
data  indicate,  allowing  even  for  the  most  rapid  development 
that  these  animals  are  capable  of.  It  would,  indeed,  be  some- 
what surprising  if  these  animals  had  not  made  an  earlier  ap- 
pearance, for  it  can  be  readily  conceived  that  at  least  some 
individuals,  more  particularly  of  the  tree-rat,  would  have  found 
their  way  over,  if  not  through  the  agency  of  vessels,  on  the 
drift  timber  which  must  at  times  have  reached  the  islands. 
The  narrative  of  Americus  Vespucins,  as  bearing  upon  the 
islands  of  Fernando  de  Noronha,  is  interesting  in  this  connec- 
tion, since  it  shows  that  these  islands,  which  lie  directly  in  the 
line  of  the  westward-sweeping  equatorial  currents,  were  in- 
habited by  a  form  of  big  rat  as  early  as  1503,  the  year  of 
Vespucius's  fourth  voyage.  How  and  whence  this  animal 
came  to  the  islands  it  is  impossible  to  say,  but  not  unlikely, 
as  has  been  suggested  by  Mr.  Wallace  and  Prof.  Branner,*  it, 
together  with  a  species  of  amphisbaBnian,  may  have  been  cur- 
rentally  distributed  from  Western  Africa,  a  supposition  that 

*Branner,  Fauna  of  the    Inlands  of  Fernando   de   Noronha — Amer.  Naturalist, 
Oct.,  1888,  p.  871. 


80  THE  BERMUDA  ISLANDS. 

seems  not  unlikely  in  view  of  certain  anomalies  of  distribution 
which  are  presented  by  the  Bermudian  fauna, 

Up  to  the  present  time  there  have  been  recorded  from  the 
Bermudas  four  species  of  bats,  two  of  which,  the  silver-haired 
bat  (  Vesperugo  noctivagans)  and  the  hoary  bat  (Atalapha  cinerea), 
are  common  North  American  forms,  while  the  remaining  two 
(Tracliyops  cirrJtosus — a  vampire — and  Molossus  rufus,  var. 
obscurus)  are  more  stricth7  tropical,  ranging  over  much  of 
South  America  and  the  West  Indian  Islands.  Specimens  of 
the  last  two,  coming  from  the  Bermudas,  are  in  the  collections 
of  the  British  Museum,  and  appear  in  Mr.  Dobson's  Catalogue 
(1878).  These  animals  must,  however,  be  of  extremely  rare 
occurrence  in  the  islands,  since  they  were  unknown  to  both 
Mr.  Jones  and  Mr.  J.  L.  Hurdis,  the  latter  a  fourteen  years 
resident.  The  silver-haired  bat  is  about  equally  rare,  as  but 
a  single  specimen  seems  to  have  been  noticed  in  the  island  group, 
and  that  one  nearly  forty  years  ago.*  Even  the  commoner 
form  (Molossus  obscurus)  is  very  uncommon,  and  appears  only 
in  the  autumn  months,  when  the  westerly  storms  bring  over 
numbers  of  American  birds.  So  rare,  indeed,  are  these 
animals  generally  that  they  are  seemingly  unknown  to  the 
majority  of  the  inhabitants,  and  even  among  the  older  resi- 
dents I  found  but  little  knowledge  of  cheiropterology.  It  is 
singular,  in  view  of  the  scarcity  of  these  animals,  that  Capt. 
Nelson  should  have  considered  the  "  red  earth  "  of  the  Ber- 
mudas,  and  also  of  the  Bahamas,  to  have  been  formed  largely 
as  an  accumulation  of  the  rejectamenta  of  bats,  which  in- 
habited "once-existing  caverns"  (Journ.  Geol.  Soc.  London, 
IX,  p.  209).  We  observed  110  bats  in  any  of  the  caves  or 
caverns  which  we  visited,  nor  did  u  ancient "  guardians  of  these 
caverns  know  anything  about  such  animals.  The  very  rare 
occurrence  of  bats  in  the  islands,  and  the  circumstance  that 
they  are  most  conspicuous  during  the  periods  of  heavy  storms, 
prove  almost  conclusively  that  these  animals  are  merely  in- 
blown  stragglers. 

*Jones,  Mammals  of  Bermuda,  op.  cit.,  p.  145- 


COCOANUT    PALMS. 


RELATIONSHIP  OF  THE  FAUNA.  81 

The  bird  fauna  of  the  Bermudas,  including  both  land  and 
water  forms,  comprises,  as  far  as  is  known,  some  187  or  188 
species,  which,  with  two  or  three  exceptions,  are  members  of 
the  North  American  fauna.  These  exceptions  are  the  sky- 
lark (Alauda  orvensis),  common  European  snipe  (Gallinago 
media),  and  gold-finch  (Carduelis  elegans).  The  first,  of  which 
but  a  single  specimen  has  been  obtained,  has  generally  been 
considered  to  be  an  escaped  cage-bird,  but  Savile  Reid,  in  his 
review  of  the  birds  of  Bermuda  (Bull.  U.  S.  National  Museum, 
No.  25,  1884,  p.  178),  believes  it  to  have  been  more  likely  an 
inblown  straggler.  Seemingly  only  two  specimens  of  the 
European  snipe  have  been  recorded,  both  of  them  from  Pem- 
broke Marsh,  where  they  wer/ shot  in  JDecftmber  1847,  by 
Colonel  Wedderburn.  The  single,  specimen  of  gold-finch  was 
observed  by  Savile  Reid  near  Harrington  Sound,  in  April, 
1875;  it  was  very  wild,  but  is  still  supposed  to  have  been 
an  escaped  prisoner.  Two  other  European  birds,  the  wheat-ear 
(Saxicola  cenanthe)  and  land-rail  ( Crex  pratensis),  have  also  been 
noted  in  the  Bermudas,  but  both  of  these  find  their  way  to 
Greenland  arid  the  mainland  of  America,  so  that  their  occur- 
rence is  less  remarkable  than  that  of  the  other  forms. 

Of  the  entire  Bermudian  avifauna  somewhat  less  than  one- 
half  the  species  are  land-birds,  and  of  these  a  fair  proportion 
have  been  observed  only  on  one  or  two  occasions.  There 
appear  to  be  but  eleven  permanent  residents,  nine  land-birds, 
and  two  water-birds,  to  wit:  cat-bird  (Galeoscoptes  Carolinensis), 
blue-bird  (Sialia  sialis),  white-eyed  vireo  ( Vireo  Noveboracensis), 
English  sparrow  (Passer  domesticus),  cardinal-bird  (Cardinalis 
cardinalis),  crow  (Corvus  Americanus),  Virginia  quail  (Colinus 
Virginianus),  ground  dove  (Columbigallina  passerina),  great  blue 
heron  (Ardea  herodias),  Florida  galliiiule  (Gallinula  galeata), 
and  tropic-bird  (Phaeton  flavirostris).  Two  or  three  species  of 
shearwater  (Puffinus  Anglorum,  P.  obscurus,  ?  P.  opisthomelas) 
have  at  intervals  been  found  breeding  in  the  Bermudas,  but 
seemingly  they  have  now  deserted  these  islands  for  other 


82  THE  BERMUDA  ISLANDS. 

quarters.*  Mr.  Savile  Reid  informs  us  that  the  presence  of 
the  Virginia  quail  or  "  bob-white  "  marks  a  recent  introduction, 
the  bird  having  entirely  disappeared  from  the  islands  with 
the  year  1840;  an  importation  from  the  United  States  was 
made  in  1858  or  1859,  and  is  the  orgin  of  the  existing  stock 
of  birds. 

Mr.  Witmer  Stone,  one  of  my  assistants,  has  furnished  me 
with  the  following  notes  on  non-resident  birds  observed  by  him 
during  our  visits  to  the  islands  in  the  month  of  July,  a  season 
of  the  year  when  the  bird  fauna  is  probably  at  its  minimum  : 

Wilson's  petrel  (Oceanites  oceanicus).  A  single  individual 
seen  in  the  wake  of  the  steamer  a  short  distance  out  from  the 
islands. 

Least  sandpiper  (Tringa  minutilld).  Several  individuals 
seen  near  Spittal  Pond.  July  15. 

Piping  plover  (JEgialitis  meloda).  A  single  individual,  which 
followed  in  the  wake  of  the  departing  steamer  for  the  better 
part  of  a  day. 

Green  heron  (Ardeavirescens).  A  single  individual  observed 
in  the  mangroves  of  Walsingham. 

We  heard  or  saw  all  the  resident  birds  of  the  islands  with 
the  exception  of  the  great  blue  heron  (Ardea  herodias).  The 
first  tropic  bird  was  seen  before  the  land  was  yet  sighted,  and 
from  this  time  until  our  departure  we  seldom  lost  sight  of  these 
beautiful  creatures.  At  the  time  of  our  visit  the  breeding  season 
was  nearly  over,  and  the  nearly  fledged  young  were  to  be  seen 
sitting  on  the  ledges  overhanging  the  waters.  The  single  egg 
is  deposited  in  holes  in  the  rock,  which  are  apparently  excavated 
by  the  parent.  We  found  the  birds  breeding  both  on  Har- 
rington Sound  and  on  the  south  shore.  The  little  English 
sparrow  was  also  found  breeding  among  the  shelving  rocks  of 
Harrington  Sound.  We  observed  but  three  crows  during  our 
sojourn,  and  it  would  appear  that  this  bird,  which  was  at 
various  times  abundant,  even  as  early  as  the  beginning  of  the 

*Mr.  Wallace  mentions  the  coot  as  a  permanent  resident,  but  probably  the  bird 
intended  is  the  gallinule. 


RELATIONSHIP  OF  THE  FAUNA.  83 

seventeenth  century,  and  as  late  as  the  last  decade,  is  again  be- 
coming rare. 

The  most  regular  and  abundant,  among  land-birds,  of  the 
"regular"  visitants  are  the  small-billed  water-thrush  (Seiurus 
Noveboracensis),  snow  bunting  (Plectrophanes  nivalis),  bobolink 
(Dolichonyx  oryzivorus),  night  hawk  (Chordeiles  Virginianus), 
and  belted  kingfisher  (Ceryle  alcyori),  some  of  which  arrive  and 
go  witli  almost  strict  punctuality  to  season.  The  pigeon-hawk 
(Hypotriorchis  columbarius)  and  osprey  (Pandion  lialiaetus),  as 
also  one  or  two  species  of  owl,  are  somewhat  less  regular,  but 
not  exactly  uncommon.  If  we  except  the  Seiurus,  all  these 
birds  are  either  partial  migrants  or  hard  fliers,  and  it  is  not 
difficult  to  account  for  their  presence  in  the  islands.  Some  of 
them,  doubtless,  reach  the  Bermudas  in  the  direct  line  of  their 
migration,  and  are  not  wind-borne.  The  regularity  of  the  ar- 
rivals proves  this  almost  beyond  question,  as  it  likewise  does 
in  the  case  of  the  numerous  water-fowl — sandpipers,  plovers, 
snipe,  etc, — which  so  largely  abound  during  the  seasons  of 
migration.  The  condition  is  otherwise  with  the  birds  that  have 
been  met  with  only  at  long  intervals  or  on  single  occasions. 
There  can  be  no  question  that  these  are  wind-swept,  and  have 
been  involuntarily  carried  seaward  by  sudden  storms.  Some 
of  the  more  delicate  birds,  such  as  the  warblers,  tits,  and  hum- 
ming-bird, have  thus  managed  to  reach  the  islands,  while, 
doubtless,  many  more  perished  in  the  interval  separating  them 
from  the  mainland.  It  is  interesting  to  note  that  even  such  a 
large  bird  as  the  American  swan  should  have  crossed  this 
stretch  of  the  ocean,  but  it  is  diffcult  to  conceive  that  the  pres- 
ence of  this  bird  is  due  to  simple  wind-drift.  May  it  not  be  a 
case  of  misdirected  flight,  following  the  lead  of  some  other 
birds?  Possibly  the  exceptional  occurrence  of  the  flamingo 
.  (Phcenicopterus  ruber)  may  be  similarly  accounted  for. 

Excluding  the  marine  turtles  which  visit  the  waters  there  is 
but  a  single  reptile  in  the  islands.  It  is  a  skink,  Eumeces 
longirostris,  a  form  closely  related  to  the  common  skink  of  the 


84  THE  BERMUDA  ISLANDS. 

Eastern  and  Southern  United  States,  Eumeces  fasciatas.  The 
animal  is  said  to  be  very  common,  but  we  saw  and  obtained 
but  a  single  specimen.  Until  within  the  last  few  years  the 
batrachians  were  wholly  wanting  from  the  Bermudas,  or  at 
least  supposed  to  be  so.  Latterly,  specimens  of  the  big  Bufo 
marinus  were  introduced,  and  seemingly  the  new  toad  does 
well.  We  saw  several  of  these  animals  in  the  brackish  waters 
near  the  Devonshire  marshes.  Not  unlikely  a  species  of 
ccecilian  also  belongs  to  the  Bermudian  fauna,  and  may 
indeed  be  indigenous.  We  obtained  from  under  a  stone  a 
number  of  eggs  beaded  to  one  another  in  the  form  of  a  string, 
which  I  was  unable  to  place.  Prof.  Ryder,  of  the  Univer- 
sity of  Pennslyvania,  has  kindly  examined  these  for  me,  and 
he  believes  that  they  are  the  eggs  of  coecilians.  They  certainly 
bear  a  very  close  resemblance  to  the  figures  and  descriptions  of 
the  ova  of  the  Coecilia,  and  most  so,  perhaps,  to  those  of  the 
genus  Coecilia  itself.  It  would  be  interesting  to  determine  to 
what  animal  the  eggs  really  belonged.  They  measured  about 
5  mm.  in  diameter. 

The  preceding  enumeration  of  species  brings  prominently 
to  light  three  important  points  in  zoogeography  :  1.  The  im- 
poverished character  of  the  vertebrate  fauna;  2,  the  distinc- 
tively American,  and  more  particularly,  North  American^ 
aspect  of  this  fauna  ;  and  3,  the  general  absence  of  forms 
peculiar  to  the  islands.  These  conditions  would  seem  to  im- 
ply a  permanent  (past)  isolation  of  the  islands  from  the  near- 
est mainland,  and  a  comparatively  brief  existence.  But  this 
need  not  necessarily  have  been  the  case.  Even  if  we  admit 
a  former  connection  with,  or  near  approach  to,  the  American 
continent,  for  which,  however,  there  appears  to  be  but  little,  if 
any,  satisfactory  evidence,  we  could  scarcely  hope,  under  the 
conditions  which  have  marked  the  history  of  the  Bermudas, 
to  have  retained  many  elements  of  a  continental  vertebrate 
fauna.  The  restricted  area  and  absence  of  freshwater,  in  con- 
junction with  the  depredations  of  birds  of  prey,  would  have 
soon  exterminated,  or  all  but  exterminated,  what  there  may 


RELATIONSHIP  OF  THE  FAUNA.  85 

have  been  of  mammals,  reptiles,  and  amphibians,  leaving  but 
a  few  groups — bats,  rodents — as  possible  survivals.  Nor  could 
we  reasonably  expect  to  find  the  remains  of  such  animals 
preserved  either  in  the  coral  rock  or  in  the  drift-rock  of  the 
islands.  With  regard  to  the  question  of  the  recent  origination 
of  the  islands  the  evidence  from  the  vertebrate  fauna  proves 
little.  The  great  distance  of  the  islands  from  the  mainland  in 
itself  explains  the  poverty  of  the  fauna,  whether  this  be  old  or 
new,  while  the  absence  of  distinctive  or  special  types  among 
birds  is,  as  Mr.  Wallace  well  holds,  due  to  the  too  frequent 
crossing  of  migrants  or  involuntary  wanderers,  which  keeps 
the  various  breeds  true,  and  prevents  specific  modification. 
The  absence  of  peculiar  species  is,  therefore,  not  a  result  of 
newness ;  on  the  contrary,  certain  considerations  seem  to  indi- 
cate that  the  island  group  is  of  greater  antiquity  than  has 
been  generally  assumed,  and  not  impossibly  some  of  the  lower 
forms  of  life  now  inhabiting  it  are  descendants  of  an  ancient 
fauna  which  was  well  developed  before  the  present  physical 
conditions  were  established. 

An  analysis  of  the  Bermudian  invertebrate  fauna  shows 
some  very  interesting  and  remarkable  features,  which  prove 
the  complexity  of  zoogeographical  inquiry.  Before  our  visit 
but  little  systematic  work — for  most  of  which  we  are  indebted 
to  Matthew  Jones— was  done  in  this  department  of  zoology, 
and,  doubtless,  much  still  remains  to  be  done.  But  the  general 
features  of  this  fauna  are  now  sufficiently  determined  to  per- 
mit of  satisfactory  conclusions  being  drawn  from  them. 

The  marine  Mollusca  of  the  archipelago,  which  up  to  the 
time  of  our  visit  were  listed  at  about  80  species,  comprise,  as 
far  as  is  now  known,  some  170  species.  These,  with  probably 
less  than  a  dozen  exceptions,  are  all  members  of  the  West 
Indian  or  Floridian  faunas.  Lying  in  the  path  of  the  Gulf 
Stream  drift,  which  strands  upon  the  island-shores  vast  quanti- 
ties of  the  Gulf-weed  (Sargassum  bacciferum),  there  seems  little 
reason  to  doubt  that  by  far  the  greater  number  of  these  forms 


86  THE  BERMUDA  ISLANDS. 

were  given  to  the  region  from  the  south.  The  species  peculiar 
to  the  Bermudas  are,  as  far  as  is  now  known,  about  eleven  in 
number,  none  of  which  had  been  described  previous  to  our 
exploration.  They  are: 

Octopus  chromatus, 

Aplysia  sequorea, 

Chromodoris  zebra, 

Onchidium  (Onchidielld)  trans- Atlanticum, 

Emarginula  dentigera, 

Emarginula  pileum, 

Csecum  termes, 

Macoma  eborea, 

Mysia  pellucida, 

Cytherea  Penistoni, 

Chama  Bermudensis. 

In  addition  to  the  above  there  are  several  shells  (Phos, 
Columbella,  Pleurotoma)  which  I  have  been  unable  to  place, 
and  which  may  prove  distinctive  of  this  fauna.  On  the  other 
hand,  it  is  not  impossible  that  some  of  the  forms  above  named 
may  be  found  elsewhere,  and  thus  lessen  the  amount  of  in- 
dividuality which  the  Bermudian  fauna  now  presents.  Thus, 
the  Murex  nuceus,  of  Morch,  which  was  supposed  to  be  peculiar 
to  the  Bermudas,  has  recently  been  found  at  Marco,  west  coast 
of  the  peninsula  of  Florida;  and  a  species  of  Cythara, 
(unnamed)  which  I  obtained  at  Shelly  Bay,  I  have  since  found 
among  unidentified  material,  from  Florida,  contained  in  the 
collections  of  the  Academy  of  Natural  Sciences.  But  the  facts 
as  they  stand  are  sufficiently  suggestive,  and  in  conjunc- 
tion with  much  more  marked  peculiarities  presented  by  the 
terrestrial  Mollusca,  point  strongly,  though  by  no  means  con- 
clusively, to  a  faunal  individuality  that  could  have  arisen  only 
as  the  result  of  long  existence,  or  of  a  faunal  modification  that 
was  unusually  rapid  in  its  development.  How  rapid  this  modifi- 
cation may  have  been,  or  how  old  the  islands  may  be,  it  is  im- 
possible to  say,  and  the  terms  can,  therefore,  only  be  used  in  a 
relative  sense;  but  with  either  condition  an  antiquity  is  indi- 


RELATIONSHIP  OF  THE  FAUNA.  87 

cated  which  extends  probably  far  beyond  the  time  that  is 
generally  associated  with  the  making  of  "recent"  coral 
islands. 

The  number  of  terrestrial  mollusks  credited  to  the  Bermudas 
is  usually  given  at  19  or  20,  but  the  list  which  appears  further 
on  shows  that  this  number  must  be  increased  to  30.  An  anal- 
ysis of  this  list  indicates  that  of  the  thirty  species  sixteen,  or 
somewhat  over  half,  are  known  also  from  the  West  Indian 
islands,  five  (Helix  vortex,  H.  microdonla,  H.  pulchella  ? ,  H. 
appressa,  and  Pupoides  fallax)  occur  in  the  United  States,  three 
in  Europe  or  the  East  Atlantic  islands  (Madeira,  Azores — Helix 
ventricosa,  Helix  pulchella,  Csecilianella  acicula),  while  not  less 
than  eight,  including  all  the  species  of  the  remarkable  group 
Pcecilozonites,  appear  to  be  confined  to  the  Bermudas.  These 
species  are :  Helix  discrepans,  Poscilozonites  Bermudensis,  P.  cir- 
cumfirmata,  P.  Reiniana,  Succinea  Bermudensis,  Alexia  Bermuden- 
sis, Mdampus  Redfieldi,  and  Helicina  convexa.  To  this  number 
may  perhaps  also  be  added  the  somewhat  doubtful  Helix 
hypolepta.  The  large  proportion  of  special  forms,  taken  in  con- 
junction with  the  development  of  a  distinct  group,  is  certainly 
remarkable  in  the  case  of  an  island  group  which  has  been 
generally  considered  to  be  recent  in  formation,  but  this  spe- 
cialization is  also  well  marked  in  some  of  the  other  animal 
groups.  The  fact  argues  for  considerable  antiquity,  and  it  is 
interesting  to  note  in  this  connection  that  the  ancestral  type  of 
the  peculiar  molluscan  genus  Poecilozonites  is  represented  in 
the  common  sub-fossil  P.  (Helix)  Nelsoni,  the  probable  progeni- 
tor of  the  recent  P.  (Helix)  Bermudensis. 

The  conditions  governing  the  dispersal  of  the  terrestrial 
Mollusca  have  been  fully  discussed  by  Mr.  Darwin  and  Mr. 
Wallace,  and  there  can  be  little  or  no  doubt  that  their  explana- 
tion of  the  oceanic  transport  of  these  animals  is  the  true  one. 
The  floating  material  of  the  Gulf-drift  has  in  this  instance, 
doubtless,  sufficed  to  bring  most,  if  not  all,  of  the  non-peculiar 
species  of  the  islands  from  the  West  Indies  and  the  Southern 
United  States.  A  few  of  the  species,  again,  may  have  been 


88  THE  BERMUDA  ISLANDS. 

transported  by  vessels,  or  even  through  the  agency  of  birds. 
The  interesting  question  here  naturally  presents  itself:  Of 
what  relation  to  the  Bermudian  fauna  are  the  two  or  three 
identical  species — Helix  ventricosa,  H.  pulchella,  and  Cdecilianella 
acicula — which  occur  in  the  East  Atlantic  islands  (Azores, 
Madeira,  Canaries)  and  Europe?  Are  they  a  part  of  the  west- 
ern fauna  which  has  gradually  drifted  eastward,  and  stocked  the 
European  continent  from  a  home  originally  insular?  The 
species  (two,  at  least)  have  seemingly  not  yet  been  found  in  the 
western  hemisphere  outside  of  the  Bermudas,  and  possibly  they 
do  not  occur  elsewhere.  If  this  is  the  case  it  is  hardly  likely 
that  they  could  have  been  carried  (except  through  the  agency  of 
man)  from  the  Bermudas  to  the  Azores  or  the  Canaries,  since 
the  first-named  islands  lie  considerably  to  the  eastward  of  the 
Gulf  current,  although  still  within  the  influence  of  the  Gulf- 
drift.  The  fact  that  none  of  the  species  of  the  peculiar  genus 
Poecilozonites  are  found  in  the  Azores  or  the  Canaries  is  a  fur- 
ther argument  against  an  assumed  eastwardly  transport.  On  the 
other  hand,  it  is  just  possible  that  the  Bermudas  have  received 
these  species  from  the  Azores  and  Canaries  through  the  return 
Lusitanian  and  equatorial  currents,  and  that  the  Azores  fur- 
nished to  Europe  the  continental  representatives  of  the  species. 
There  would  be  nothing  strange  in  this,  and  the  northern  posi- 
tion of  the  return  currental  flow  might  explain  the  absence  of 
these  forms  from  the  West  Indian  Islands.  That  islands,  which 
are  favorably  situated  as  far  as  winds  and  currents  are  con- 
cerned, should  have  transmitted  to  continental  areas  portions 
of  their  faunas  is  what  we  should  but  expect.  It  is  not  only 
that  the  continents  furnish  the  islands,  but  necessarily  the 
islands  must  furnish  the  continents,  but  to  what  extent  this 
reciprocal  action  takes  place  cannot  well  be  determined.  From 
various  considerations  Morelet  has  argued  that  some  of  the 
molluscan  forms  of  meridional  Europe  must  have  originated 
in,  or,  at  least,  been  derived  from,  the  Azores.  If  the  ocean 
currents  which  now  pass  off  the  Southeastern  United  States 
trended  in  the  opposite  direction  there  can  be  no  question  that 


RELATIONSHIP  OF  THE  FAUNA.  89 

some  of  the  peculiar  land-snails  of  the  Bermudas  would  be 
drifted  to  our  shores,  where,  with  a  favorable  climate  and  vege- 
table growth,  they  would  soon  multiply  and  spread,  and  to 
such  an  extent  as  to  make  it  appear  as  though  they  originated 
on  the  continent. 

It  might  be  objected  that  these  seeming  anomalies  of  dis- 
tribution can  be  readily  accounted  for  by  assuming  that  there 
has  been  simple  artificial  transport  by  means  of  vessels.  And, 
no  doubt,  full  allowance  must  be  made  for  this  contingent  dis- 
tribution. But,  again,  on  this  assumption  the  absence  of  the 
commonest  species  of  land  mollusks — those  which  have  been 
most  broadly  distributed  over  the  earth's  surface,  and  which 
would  have  found  congenial  conditions  of  environment  in  the 
Bermudas — becomes  very  striking,  and  equally  so  whether  we 
consider  the  forms  that  may  have  been  transported  from  the 
Old  World  or  from  the  New. 

The  marine  molluscan  fauna  of  the  Bermudas  is,  as  has 
already  been  seen,  overwhelmingly  Antillean  in  character,  and 
there  can  be  no  question  that  its  owrn  history  is  intimately 
bound  up  with  the  history  of  the  fauna  of  the  West  Indies. 
The  practically  total  absence  of  species  of  the  Eastern  United 
States  which  are  not  found  in  the  Floridian  waters  is  astonish- 
ing, and  shows  how  insuperable  is  the  barrier  which  the  waters 
of  the  Atlantic,  and  of  the  Gulf  stream  particularly,  offer  to  a 
free  migration  or  dispersion  of  the  species.  This,  again,  ap- 
pears the  more  remarkable  in  the  light  of  certain  anomalies  of 
distribution  which  a  critical  examination  of  the  species  reveals, 
and  which  had  already  in  many  cases  been  noted  as  a  charac- 
teristic of  the  West  Indian  fauna.  Thus,  the  various  species  of 
Triton,  Triton  chlorostoma,  T.  tuberosum,  T.  cynocephalus  and  T. 
jtilcare,  are  all  members  of  the  fauna  of  the  Pacific  and  Indian 
oceans ;  Ranella  cruentata  crops  up  in  the  variety  R.  rhodostoma, 
from  Mauritius.  Again,  Epidromus  concin nus,  from  the  Philip- 
pines, is  represented  in  our  collection  by  a  number  of  individ- 
uals which  are  absolutely  undistinguishable,  both  in  shell  or- 
namentation and  color-markings,  from  the  Pacific  specimens, 


90  THE  BERMUDA  ISLANDS. 

while  they  differ  somewhat  from  the  closely  related  Epidromus 
Swifti,  from  Antigua.  A  seemingly  undescribed  form  of  Col- 
umbella  (Anachis)  is,  so  far  as  I  have  been  able  to  determine, 
most  nearly  related  to  a  species  from  New  Caledonia,  Anachis 
plicaria  ;  Natica  Marochinensis  is  a  member  of  the  faunas  of  both 
Western  Africa  and  the  Pacific,  and  Natica  lactea  is  apparently 
undistinguishable  from  N.  Flamingiana,  from  the  Viti  (Feejee) 
Islands,  Philippines,  etc.,whence  we  have  also  the  Area  imbricata- 
A  number  of  forms  common  to  the  west  coast  of  Africa  and  to 
the  southern  waters  of  Europe  also  occur,  but  these  appear  to 
be  less  numerous  than  the  forms  which  occur  in  the  Pacific 
and  Indian  oceans.  Seemingly  but  few  of  the  Bermudian 
species  are  found  in  the  Azores  (Purpura  hsemastoma,  Neritina 
viridis,  Avicula  Atlantica,  Pinna  rudis),  a  somewhat  surprising 
circumstance  in  view  of  the  large  representation  of  Pacific  forms, 
and  considering  that  the  Azores  lie  directly  in  the  path  of  the 
heated  waters  of  the  Gulf  Stream.  It  is,  indeed,  difficult  to 
account  for  these  anomalies  of  distribution,  and  for  still  more 
marked  ones,  as  we  shall  presently  see,  which  are  presented  by 
the  Crustacea. 

Of  molluscan  forms  which  have  been  hitherto  considered 
to  be  restricted  to  the  west  coast  of  America,  I  can  state  the 
positive  'occurrence  of  only  two  or  three  species — Chama 
exogyra,  Tellina  Gouldii,  from  the  Californian  coast.  In  the 
case  of  both  of  these  forms  I  have  very  carefully  satisfied  my- 
self as  to  absolute  identity.  Area  solida,  from  the  west  coast, 
does  not  appear  to  differ  measurably  from  Area  Adamsi, 
a  West  Indian  form  which  has  its  representative  in  the  Ber- 
mudian fauna.  I  feel  satisfied  that  many  more  forms  are 
common  to  the  east  and  west  coasts  of  America  than  is 
generally  assumed  to  be  the  case. 

There  appears  to  have  been  no  systematic  determination  of 
the  Bermudian  Crustacea  prior  to  our  visit  to  the  islands. 
The  collections  made  by  us  are  not  extensive,  but  probably  a 
full  half  of  the  species  which  they  contain  are  now  for  the 
first  time  recorded  from  the  archipelago.  By  far  the  greater 


RELATIONSHIP  OF  THE  FAUNA.  91 

number  of  species — indeed,  nearly  all  of  them — are,  as  would 
be  naturally  expected,  forms  which  belong  to  tropical  or  sub- 
tropical America  (Florida,  West  Indies,  Brazil).  None  of  the 
species,  as  far  as  they  have  been  determined — the  Isopoda  and 
Amphipoda  still  await  examination — are  peculiar  to  the  Ber- 
mudas, excepting  possibly  Scyllarus  scvlptus.  The  specimen 
figured  by  Lamarck  in  the  Encyclopedic,  and  subsequently  de- 
scribed by  Milne-Edwards,  seems  to  have  been  "without  a 
home,"  nor  have  I  been  able  to  trace  the  species  from  the  writ- 
ings of  later  authors.  I  am,  therefore,  not  in  a  position  to  say 
whether  the  species  is  strictly  Bermudian  or  not. 

The  remarkable  fact  connected  with  the  Bermudian  Crus- 
tacea is  the  appearance  of  three  species  of  Macrurans  which 
had  hitherto  been  recorded  only  from  the  Pacific.  These  are 
Palsemondla  tenuipes,  described  by  Dana  from  the  Sooloo  Sea. 
Pal  demon  affinis,  and  Penseus  velutinus,  the  last  a  species  also 
first  described  by  Dana.  It  is  remarkable  that  the  only 
species  of  Palaemonella  other  than  P.  tenuipes  is  likewise  an 
inhabitant  of  the  Sooloo  Sea.  I  am  wholly  at  a  loss  how  to 
account  for  the  occurrence  of  these  Pacific  types  at  the  Ber- 
mudas; they  may  yet  be  discovered  in  some  intermediate 
region,  and  thereby  lessen  the  difficulty  in  the  problem,  but 
for  the  time  being  their  presence  must  be  considered  a  zoogeo- 
graphical  knot  to  be  cut.  The  absence  of  the  common  Paldemon 
vulgaris,  as  well  as  of  the  principal  crustaceans  of  the  Eastern 
United  States,  excepting  the  more  southerly  forms,  is  strik- 
ingly noticeable.  Alpheus  avarus  is  a  Eurafrican  form  ; 
Pachygrapxus  transversus  has  been  noted  also  from  Australia. 

The  insect  fauna  (including  here  also  the  spiders)  of  the  Ber- 
mudas is  distinguished  more  by  negative  features  than  by 
positive  ones;  it  is  eminently  deficient.  It  is  not  yet  known 
in  its  full  details,  but  sufficiently  so  to  show  that  it  is  mainly  a 
combination  of  Neotropical  (West  Indian  and  South  Ameri- 
can) and  Holarctic  (North  American)  elements.  And  here  we 
are  presented  with  the  significant  fact  that  the  insects  proper 


92  THE  BERMUDA  ISLANDS. 

or  fliers  are  essentially  forms  common  to  temperate  United 
States,  while  the  non-fliers  or  arachnids  are  more  nearly  trop- 
ical or  sub-tropical  forms,  or  such  as  have  required  drift 
material  to  transport  them  to  their  present  habitation.  The 
former  have  evidently  been  carried  across  the  interposing  arm 
of  the  sea  in  the  manner  of  the  rarer  birds — i.e.,  through  the 
instrumentality  of  storms.  Dr.  P.  R.  Uhler,  who  has  kindly 
looked  over  our  collections  of  Orthoptera,  Neuroptera,  etc.,  in- 
forms us  that  strong  winds  blowing  off  the  mainland  of  Mary- 
land and  Virginia  carry  countless  numbers  of  nearly  all  kinds 
of  insects  out  over  the  ocean,  and  that  those  that  are  dropped 
into  the  sea  are  "  returned  to  the  shores  by  the  tides  and  piled 
up  in  windrows  along  the  beaches.  Among  these  we  have 
often  found  the  half-drowned  dragon  flies  mixed  in  with  the 
thick  piles  of  beetles,  bugs,  wasps,  and  flies  which  stretched 
along  the  line  of  the  retreating  tide."  That  many  thus  wind- 
swept reach  to  distances  at  least  as  remote  as  the  Bermudas 
there  can  be  no  question. 

We  observed  during  our  brief  sojourn  but  four  butterflies, 
Danais  archippus,  Pyramis  Atalanta,  P.  cardui,  and  Junonia  cnenia, 
all  common  forms  of  the  United  States,  and  these  appear  to  be 
nearly  all  the  forms  that  are  usually  met  with  in  the  islands. 
Three  or  four  other  species  of  day-fliers  have  been  observed  at 
different  times,  but  they  are  of  such  rare  occurrence  as  to 
barely  constitute  true  elements  of  the  Bermudian  fauna.  Our 
beetles  were  limited  to  some  five  or  six  species,  which  Dr.  Horn 
has  kindly  determined  for  me  to  be  Ligyrus  tumulosus,  L.  gib- 
bosus,  Agonoderus  lineola,  Cicindela  tortuosa,  and  Opatrinus 
anthracinus,  forms  common  to  Cuba  and  the  Southern  United 
States.  A  number  of  other  species  of  Coleoptera  have  been 
collected  in  the  islands,  but  I  am  not  aware  that  they  have  as 
yet  been  carefully  determined. 

From  the  list  of  Orthoptera,  Pseudoneuroptera,  and  Dermop- 
tera  which  Dr.  Uhler  has  prepared  for  me  it  will  be  seen  that 
they  represent  types  which  are  included  in  the  United  States 
fauna  of  the  region  between  Cape  Cod  and  Florida.  Dr. 


RELATIONSHIP  OF  THE  FAUNA.  93 

Uhler  calls  attention  to  the  significant  fact  that  two  of  the 
Pseudoneuropters,  Mesotliemis  longipennis  and  Lestes  unguiculata, 
are  freshwater  types,  whose  larval  condition  is  dependent 
upon  the  existence  of  fresh,  or  hut  mildly  brackish,  waters. 
The  Bermudian  earwig  (Labidura  riparia — Forficula  gigantea)  is  a 
species  recently  introduced  into  the  Eastern  United  States 
from  the  Mediterranean  region. 

Prior  to  1888  there  were  but  six  species  of  spiders  recorded 
from  the  Bermudas,  of  which  three  were  described  as  peculiar 
by  Blackwall — Salticus  diversus,  Xysticus  pallidus,  and  Epeira 
gradlipes.  To  this  number  we  now  add  eleven  additional 
forms,  one  of  which,  Lycosa  Atlantica  of  Marx,  proves  to  be 
new.  Dr.  Marx,  of  Washington,  has  kindly  determined  all 
of  our  forms,  and  his  notes  on  species  appear  on  another  page. 
The  thirteen  species  which  are  not  peculiar  to  the  Bermudas 
are  the  following : 

Loxosceles  rufescens,     .         W.    Indies,    Florida,    Europe,   Asia, 

Africa,  Madeira,  Canaries,  Cape 

Verde  Islands. 

Heteropoda  vcnatoria,  .         Cosmopolitan. 
Filistata  depressa,        .        Southern  United  States. 
Uioborus  Zosis,    .        .        W.  Indies,  Florida,  S.  Amer.,  Africa, 

Asia,  S.  Helena. 

Nephila  clavipes, .         •.'••       S.  United  States,  S.  and  C.  America. 
Epeira  caudata,  .         .         United  States. 
Epeira  labyrinthea,     .        N.  and  S.  America  (to  Magellan),  W. 

Indies. 

Theridium  tepidariorum,     America,  Europe,  Azores,  S.  Helena. 
Argyrodes  nephilse,      .         United  States,  Guiana,  Peru. 
Pholcus  tipuloides,    ^        Samoa. 
Dysdera  crocata,  .      - ,        U.  S.,  Europe,  Azores,  Canaries,  S. 

Helena. 

Menemerus  Paykullii,  .         Cosmopolitan  ? 
Menemerus  melanognathus,  America,   Europe,  Africa,  Canaries, 

Cape  Verde  I.,  S.  Helena. 


94  THE  BERMUDA  ISLANDS. 

The  remarkably  broad  and  somewhat  indiscriminate  distri- 
bution of  most  of  these  species  shows  almost  beyond  doubt 
that  they  have  been  principally  or  largely  transported  through 
the  agencies  of  commerce.  They,  therefore,  throw  but  little 
light  upon  the  subject  of  zoogeography,  although  it  is  interest- 
ing to  find  that  such  a  large  number  of  forms  can  so  readily 
accommodate  themselves  to  the  varied  conditions  of  climate,  and 
of  the  surroundings  generally,  which  the  different  countries 
present.  The  proportion  of  peculiar  forms  is  greater  than  we 
should  have  expected  to  find  in  a  region  which  is  in  such  fre- 
quent communication  with  the  mainland,  and  is  supposed 
to  be  of  comparatively  recent  origin.  But,  as  has  already 
been  seen,  there  are  good  grounds  for  believing  that  the 
islands  are  more  ancient  than  they  are  generally  considered 
to  be — or,  at  least,  that  their  fauna  is.  Mr.  Bollman  has  de- 
termined four  species  of  myriapods  in  our  collections,  one  of 
which,  a  Spirobolus,  is  apparently  peculiar  to  the  islands.  Of 
the  remaining  forms,  as  far  as  it  has  been  possible  to  determine 
from  imperfect  specimens,  one  of  the  species  is  from  the 
Azores,  another  from  Europe,  and  the  third  from  the  United 
States.  Of  course  the  number  of  species  collected  is  not 
sufficiently  great  to  give  positive  values  in  the  matter  of 
distribution. 

Of  the  lower  groups  of  animals,  such  as  the  sponges,  corals, 
and  echinoderms,  we  have  principally  Antillean  and  Floridian 
types  represented.  That  this  should  be  the  case,  more  par- 
ticularly with  the  reef-building  corals,  stands  to  reason.  It  is 
less  easy  to  account  for  the  large  number  of  peculiar  or  new 
forms  among  the  holothurians,  unless  it  be  on  the  assumption 
of  antiquity.  But  they  may  yet  be  discovered  elsewhere,  in 
the  West  Indies,  although  if  they  existed  in  the  Bahamas, 
where  we  should  naturally  expect  to  look  for  them,  they  could 
scarcely  have  failed  to  attract  the  eyes  of  the  different  natural- 
ists who  have  from  time  to  time  visited  the  islands.  They  are 
in  the  Bermudas  about  the  most  conspicuous  objects  on  the 
coral  sands. 


RELATIONSHIP  OF  THE  FAUNA.  95 

In  summarizing  the  general  features  of  the  Bermudian 
fauna  as  they  have  been  passed  in  review  in  the  preceding 
pages  the  following  broad  conclusions  and  facts  present  them- 
selves : 

1.  The  Bermudian  fauna  is  essentially  a  wind-drift  and  cur- 
rent-drift fauna,  whose  elements  have  been  received  in  prin- 
cipal part  from  the  United  States  and  the  West  Indies.     The 
aquatic  animals  are  overwhelmingly  Antillean  in  character, 
while  the  animals  of  the  air — birds  and  insects — are  as  over- 
whelmingly North  American. 

2.  Some  portion  of  the  fauna  appears  to  have  been  derived 
(through  the  agency  of  the  return  Atlantic  current)  from  the 
wrest  coast  of  Eurafrica  (including  the  African  Islands),  or  even 
from  the  Azores,  while  probably  but  few  forms,  if  any,  wrere 
given  to  those  regions  by  the  Bermudas. 

3.  The  large  proportion  of  peculiar  forms  among  the  terres- 
trial Mollusca  more  particularly ,  and  somewhat  less  so  among  the 
arachnids  and  echinoderms,  renders  it  probable  that  this  fauna 
is  in  part  of  considerable  antiquity,  and  that  some  of  its  ele- 
ments  have   been   developed   from    a   fauna   pre-existent   in 
the  region  when  .the  present  physical  conditions  had  not  yet 
been  established.      This  conclusion  is  supported  by  the  fact 
that  the  predecessor  of  a  group  of  Pulmonata  now  peculiar  to 
the  islands  is  found  fossil  or  sub-fossil  in  the  rock  of  these 
islands. 

4.  Certain  marked  elements  of  the  Bermudian  fauna  are  of 
a  distinctively  Pacific  type — Mollusca,  Crustacea — but  it  seems 
impossible  at  the  present  time  to  explain  this  mixed  relation- 
ship. 

5.  The  currental  wrater  which  separates  the  United  States 
from  the  Bermudas  proves  a  practically  insuperable  barrier  to 
the  direct  passage  of  marine  animals  from  the  one  region  to 


96  THE  BERMUDA  ISLANDS. 

the  other ;  hence,  the  forms  of  the  Eastern  United  States,  except 
in  so  far  as  they  may  be  also  members  of  the  southern  fauna, 
are  almost  entirely  absent  from  the  Bermudas. 

6.  Most  of  the   temperate-American   element   of  the  Ber- 
mudian  fauna  owes  its  establishment  on  the  islands  to  acci- 
dental causes — storm-winds ;  the  tropical  (Neotropical  element) 
is,  on  the  other  hand,  the  expression  of  slow  but  steady  diffusion. 

7.  Neotropical  elements  largely  preponderate  in  the  perma- 
nent or  resident  fauna  of  the  islands. 

8.  An  arm  of  the  sea  may  be  as  insuperable  a  barrier  to  the 
passage  of  marine  animals  as  it  would  be  to  the  animals  of  the 
land ;    caution  is  hence  necessary  in  the  discussion  of  conti- 
nental and  oceanic  changes  or  stability  as  affecting  animal 
distribution. 


1 


VI. 


ZOOLOGY  OF  THE  BERMUDAS. 


The  following  notes  on  the  zoology  of  the  Bermudas  are 
based  on  personal  observations,  and  on  collections  made  dur- 
ing a  brief  sojourn  011  the  islands  during  the  past  summer,  in 
company  with  a  class  of  students  from  the  Academy  of  Natural 
Sciences.  But  little  systematic  work,  other  than  that  in  the 
departments  of  ornithology,  ichthyology,  and  botany,  had 
hitherto  been  done  in  this  remarkably  interesting,  and  typi- 
cally oceanic,  island  group,  and  it  was  thought  that  a  more 
critical  survey  might  bring  out  facts  of  general  interest  to  the 
zoological  student,  and  throw  some  additional  light  upon  the 
intricate  subject  of  zoogeography.  In  the  results  obtained  I 
have  not  been  disappointed.  The  exuberance  of  animal  life 
has  yielded  much  that  has  proved  to  be  new  to  the  systematist, 
while  certain  remarkable  peculiarities  in  the  distribution  of  a 
number  of  well-known  types  of  animals  open  up  vistas  in  geo- 
graphical distribution  which  appear  to  me  at  present  to  recede 
into  darkness,  and,  perhaps,  tend  to  draw  only  more  closely  the 
veil  over  this  mysterious  subject. 

The  specimens  noted  or  described  in  the  following  pages 
were  largely  obtained  through  dredgings,  which  were  carried 
on  as  well  in  the  outer  water  as  in  the  smaller  interior  sounds 
and  lagoons.  As  might  have  been  anticipated  the  greatest 
profusion  of  animal  life  was  found  on  the  edge  of  the  growing 
reef  itself,  the  shoals  surrounding  the  cluster  of  rocks  on  the 
northern  barrier  known  as  the  North  Rock.  The  wealth  of 
forms  occurring  here  almost  transcends  belief;  unfortunately, 
the  limited  time  at  our  command  and  the  state  of  the  weather 


98  THE  BERMUDA  ISLANDS. 

prevented  more  than  a  cursory  examination  of  this  locality, 
which  is  made  comfortable  for  collecting  and  wading  during  a 
partial  exposure  above  water  of  some  three  hours.  All  the 
dredgings  were  confined  to  depths  within  16  fathoms,  which 
also  represents  the  greatest  sounding  made  by  us  in  the  lagoons. 

ACTINOZOA. 

The  true  stone  corals  of  the  Bermudas  are  comprised,  so  far 
as  we  now  know,  in  some  twenty-five  species,  the  greater  number 
of  which  are  represented  by  identical  forms  in  the  Bahaman  or 
West  Indian  seas.  The  genera  thus  far  indicated  are  Oculina, 
Mycedium,  Astrzea,  Siderastrsea,  Forties,  Isophyllia,  Mseandrina, 
and  Diploria.  The  genus  Madrcpora,  one  of  the  commonest  of 
the  Bahaman  and  Floridian  corals,  appears  to  be  absent.  On 
the  south  and  east  side  of  the  island  group  the  outer  margin 
of  the  growing  reef,  largely  covered  by  a  serpuline  and  ver- 
metus  growth,  approaches  to  within  a  few  hundred  feet  of  the 
shore,  where  it  breaks  the  inflowing  surf  into  a  white  crest. 
Within  the  line  of  these  breakers  the  depth  of  water  is  in 
places  as  much  as  ten  or  twelve  fathoms.  The  brain  coral 
(Diploria}  and  various  gorgonians  develop  here  in  great  profu- 
sion, the  huge  yellow  masses  of  the  former  appearing  almost 
everywhere  at  depths  of  from  ten  to  twenty  feet.  Vast  growths 
of  millepore  also  cover  the  shallower  bottoms,  presenting  in 
the  ensemble  a  wonderful  garden  of  animal  development. 
This  profusion  of  coral  growth  is,  however,  surpassed  on  the 
north  side,  where  the  reef  recedes  to  a  distance  of  some  eight 
or  nine  miles  from  the  island-shores,  enclosing  an  extensive 
body  of  water  whose  depth  is  in  general  about  eight  or  ten 
fathoms,  and  more  rarely  twelve  fathoms.  Much  the  same 
coral  growth  is  indicated  here  as  on  the  south  side,  the  large 
brain-corals  preponderating  by  their  masses.  While,  probably, 
the  greatest  profusion  of  animal  life  is  really  met  with  on  the 
actual  edge  of  the  growing  reef,  this  does  not  appear  to  be  the 
case  with  the  corals  themselves.  At  any  rate,  I  was  unable  to 
satisfy  myself  that  there  was  any  marked  difference  to  be  ob- 


ZOOLOGY  OF  THE  BERMUDAS.  99 

served  between  the  marginal  growth  and  that  which  extends 
gradually  backward  from  the  margin  into  deep  water.  In- 
deed, as  far  as  the  brain-corals  themselves  are  concerned,  it 
appeared  to  me  that  their  largest  masses  were  to  be  found 
some  distance  within  the  bounding  reef,  and  consequently  be- 
yond the  breaking  action  of  the  surf.  This  condition  is  again 
shown  in  the  comparatively  quiet  and  sheltered  waters  of  Cas- 
tle Harbor,  where  portions  of  the  platform-bottom  may  be  said 
to  constitute  one  almost  connected  mosaic  of  huge  Diplorias. 
In  so  far,  therefore,  the  Bermudas  differ  from  the  greater  num- 
ber of  coral  islands,  in  which,  as  is  commonly  stated,  there  is 
a  marked  deficiency  in  the  coral  growth  within  the  bounding 
area,  and  an  equally  marked  luxuriance  on  the  crest  and  outer 
slope  of  the  reef. 

In  most  places  the  largest  corals  do  not  come  nearer  than  a 
foot  or  two  feet  of  the  surface  of  the  water,  the  massive  brain- 
corals  rarely  appearing  in  water  of  less  depth  than  five  or  six 
feet.  But  in  the  shallows  off  the  North  Rock  we  found  Porites 
astraeoidcs  almost  at  the  surface  in  low  water,  and  just  off 
the  entrance  to  Harrington  Sound,  on  the  north  shore,  Sideras- 
trsta  galaxea  was  covered  by  only  about  two  inches  of  water. 
The  borders  of  Harrington  Sound  are  largely  overgrown  with 
species  of  Isophyllia,  which  likewise  approach  to  within  a  short 
distance  of  the  surface.  In  the  greater  depths  of  the  Sound  we 
found  only  Oculina,  down  to  ten  fathoms,  the  dredge-net  being 
frequently  caught  and  reversed  by  their  ramose  stems ;  beyond 
ten  fathoms  the  dredge  usually  came  up  empty. 

The  following  species  were  obtained  by  us : 

Mycedium  fragile,  Dana. 

Two  specimens.     North  Rock  ? 

Oculina  diffusa,  Lamk. 

Harrington  Sound. 

Oculina  varicosa,  Lesueur. 

Harrington  Sound. 

Oculina  pallens,  Ehrenberg. 

Harrington  Sound. 


100  THE  BERMUDA  ISLANDS. 

I  feel  satisfied  that  this  species  is  identical  with  the  preced- 
ing, the  same  stock  bearing  what  might  be  considered  to  be 
typical  representatives  of  both  forms. 

The  amount  of  variation  in  the  disposition  of  the  calyces,  as 
well  as  in  their  individual  shape,  is  very  great  in  this  genus, 
and  I  am  by  no  means  sure  that  two  or  three  of  the  other  forms 
of  Oculina  here  enumerated  represent  anything  more  than 
varietal  modifications.  Pourtales,  in  his  illustrations  of  the 
corals  of  the  Florida  reefs  (Mem.  Mus.  Comp.  Zoology,  VII, 
plates  I  and  II)  correctly  refers,  it  seems  to  me,  both  types  to  a 
single  species  (0.  varicosd). 

Oculina  speciosa,  Edwards  and  Haime. 

Harrington  Sound. 

Oculina  recta,  Quelch. 

One  specimen,  from  Harrington  Sound,  which  agrees  in  the 
characters  of  the  species  from  St.  Thomas  (Quelch,  Challenger 
Reports,  Zoology,  XVI,  p.  51).  The  species  does  not  appear 
to  have  been  hitherto  observed  in  the  Bermudian  waters. 

Oculina  coronalis,  Quelch. 

Harrington  Sound.  First  described  from  the  Bermudas 
(Challenger  Reports,  Zoology,  XVI,  p.  49.) 

Quelch,  in  his  report  on  the  reef-building  corals  of  the 
Challenger  (op.  tit.,  pp.  9  and  49),  enumerates  as  an  additional 
member  of  the  Bermudian  fauna  the  Oculina  Bermudiana  of 
Duchassaing  and  Michelotti.  I  have  been  unable  to  find  any- 
thing in  the  description  or  figures  furnished  by  these  authors 
(Supplement  au  Memoire  sur  les  Coralliaires  des  Antilles,  p.  162, 
pi.  IX,  figs.  1,  2 — Memorie  delta  Reale  Accad.  Seienze  di  Torino, 
Ser.  Sec.,  XXIII,  1866)  to  distinguish  their  species  from 
Oculina  speciosa,  nor  does  it  appear  to  me  to  be  distinct.  The 
characters  upon  which  the  form  is  separated  are  exceedingly 
trivial,  and  well  within  the  amount  of  variability  which  is 
presented  by  individual  specimens  of  nearly  all  the  species  of 
Oculina.  I  further  believe  that  0.  coronalis,  and  possibly  also 
0.  recta,  will  have  to  be  united  with  0.  speciosa. 


ZOOLOGY  OF  THE  BERMUDAS.  101 

Isophyllia  australis  T  Edwards  and  Haime. 

Three  specimens  from  the  North  Rock,  doubtfully^  indenti- 
fied  with  this  species. 

Isophyllia  fragilis  ?  Dana. 

I  am  unable  to  satisfy  myself  as  to  the  positive  existence  of 
this  species  in  Bermuda,  although  Quelch  refers  to  a  single 
specimen  having  been  obtained  there  by  the  Challenger  party. 
This  authority  doubtfully  refers  one  of  the  forms  figured  by 
Pourtales  (op.  cit.,  pi.  VII,  fig.  3)  as  /.  dipsacea  to  Dana's 
species,  but  from  an  examination  of  a  number  of  Bermudian 
specimens  which  agree  absolutely  with  Pourtales's  figure  I  am 
fairly  convinced  that  this  identification  is  incorrect.  The 
specimens  do  certainly  not  agree  sufficiently  with  Dana's  de- 
scription, and  if  they  are  not  the  types  of  a  distinct  species, 
then  they  represent  probably  only  a  pertain  phase  of  develop- 
ment of  /.  dipsacea,  as  is  indicated  by  Pourtales. 

Isophyllia  dipsacea,  Dana. 

Three  specimens,  from  Castle  Harbor. 

Isophyllia  strigosa.  Duchassaing  and  Michelotti 

A  number  of  specimens,  from  Harrington  Sound,  which 
agree  with  the  description  of  this  species.  I  am  doubtful  as 
to  the  species  being  distinct  from  Isophyllia  dipsacea]  possibly, 
however,  some  of  the  varieties  (so-called)  of  the  latter  species 
figured  by  Pourtales  are  really  members  of  this  species.  Its 
principal  distinguishing  characters  appear  to  be  the  thinner 
and  more  irregular  septa,  and  the  terminal  cleft  that  indents 
or  separates  the  septa  of  opposing  calyces  where  they  cross  the 
common  wall.  It  also  presents  a  more  bristling  appearance 
than  I.  dipsacea. 

Isophyllia  Guadeloupensis,  Portal  es. 

One  specimen.  This  appears  to  be  a  good  species,  although 
by  Quelch  it  is  referred  to  Isophyllia  strigosa. 

In  addition  to  these  forms  Quelch  enumerates  Isophyllia 
(Symphyllia)  marginata,  I.  cylindrica,  and  /.  Knoxi,  all  of 
Duchassaing  and  Michelotti,. as  having  been  obtained  at  the 


102  THE  BERMUDA  ISLANDS. 

Bermudas,  but  I  have  failed  to  detect  any  specimens  among 
our  collections  which  can  be  confidently  referred  to  these 
species.  On  the  other  hand,  I  find  one  or  two  forms  which  I 
have  not  yet  been  able  to  identify  with  any  described  forms. 

Siderastraea  galaxea,  Ellis  and  Solander. 

Abundant  on  the  shoals  of  Gallows  Island,  near  the  mouth 
of  Flatts  Inlet,  where  the  colonies  come  to  within  about  two 
inches  of  the  surface ;  also  on  the  borders  of  Harrington  Sound. 

Porites  clavaria,  Lamk. 

Two  specimens,  dredged  in  Harrington  Sound. 

Porites  astraeoides,  Lamk. 

We  found  this  species  very  abundantly  along  the  outer  reef, 
especially  on  the  flats  of  the  North  Rock,  where  it  is  the  domi- 
nant form  of  coral.  The  species  appears  to  have  been  over- 
looked by  the  Challenger  party,  and  indeed,  the  only  reference 
that  I  have  been  able  to  find  indicating  the  occurrence  of  this 
common  West  Indian  form  among  the  Bermudas  is  contained 
in  Mr.  Rathbun's  list  of  the  species  of  Porites  in  the  United 
States  National  Museum  (Proc.  U.  S.  National  Museum,  1887, 
p.  354). 

Maeandrina  labyrinthica,  Ellis  and  Solander. 

Three  specimens,  from  the  North  Rock. 

Maeandrina  strigosa,  Dana. 

This  form  is  represented  by  large,  sub-globose  specimens, 
one  of  which,  obtained  through  purchase,  and  probably  from 
Castle  Harbor,  has  an  exceedingly  attenuated  base  of  attach- 
ment. The  corallum  is  thus  openly  turbinate,  or  even  pedicu- 
late,  and  exhibits  in  its  regular  scalariform  outline  the  succes- 
sive stages  of  outward  development. 

Diploria  cerebriformis,  Lamk. 

This  species  is  exceedingly  abundant  in  the  shoals  lying  to 
the  leeward  of  the  marginal  reef,  where  its  huge  hemispheri- 
cal or  reniform  masses  of  bright  orange,  measuring  as  much 
as  four  or  five  feet  in  diameter,  can  be  distinctly  seen  through 


ZOOLOGY  OF  THE  BERMUDAS.  103 

the  transparent  waters  at  depths  of  from  six  to  fifteen  or 
twenty  feet.  I  cannot  say  how  much  further  down  the  species, 
extends.  It  is  equally  abundant  in  Castle  Harbor,  where  it  is 
largely  instrumental  in  building  out  the  shore-platform  which, 
at  a  moderate  distance  from  the  shore,  descends  vertically  into 
deeper  water.  When  attached  by  a  contracted  base,  the  brain- 
coral  may  be  readily  removed  from  its  moorings;  but  where 
the  base  is  largely  coextensive  with  the  under-surface  of  the 
corallum  the  difficulties  of  removal  are  very  great,  necessitat- 
ing much  undercutting  with  a  chisel.  The  largest  specimen 
obtained  by  us  measured  about  28  inches  across ;  our  efforts  to 
dislodge  a  specimen  about  four  feet  in  diameter  proved  un- 
successful. 

Diploria  Stokesi,  Edwards  and  Ilaime. 

We  obtained  a  number  of  specimens  of  this  species  in  Castle 
Harbor,  and  through  presentation  ;  for  the  latter  my  thanks 
are  due  to  Miss  A.  Peniston,  of  Peniston's.  The  habitat  of  the 
species,  as  far  as  I  am  aware,  has  not  hitherto  been  noted. 
Edwards  and  Haime  in  their  description  of  the  species  (Hist. 
Nat.  des  Coralliaires,  II,  p.  403,  pi.  D,  fig.  3)  state  "  Patrie  incon- 
nue"  I  believe  it  may  be  assumed  that  this  species  is  the 
form  described  and  figured  by  Knorr  as  Madrepora  labyrinthi- 
formis  (Delicise  Naturae  Selects,  I,  p.  18,  PI.  A  4,  fig.  1).  In  our 
collections  we  have  a  closely  related,  and  possibly  identical, 
species,  which  assumes  a  ring  form,  and  in  which  the  peculiar 
calycular  hollows  of  D.  Stokesi  run  out  into  parallel  transverse 
grooves  on  the  inner  side  of  the  ring. 

ALCYONARIA. 

The  gorgonians  are  abundant  in  the  waters  inside  of  the 
bounding  reef,  whence  nearly  all  our  specimens  were  obtained. 
A  few  were  nipped  up  on  the  south  side  of  Castle  Harbor,  and 
at  the  passage  way  conducting  from  the  north  into  that  body 
of  water. 

Rhipidogorgia  flabellum,  Valenciennes, 

The  purple  variety  of  this  species  is  abundant  more  par- 
ticularly in  the  northern  waters,  both  near  the  outer  reef  and 


104  THE  BERMUDA  ISLANDS. 

on  the  shallows  known  as  Devonshire  Flats.  We  failed  to 
obtain  any  of  the  yellow  forms,  and  I  am  not  positive  that 
this  variety  has  ever  been  found  at  the  Bermudas. 

Gorgonia  (Plexaura)  purpurea,  Pallas. 
Gorgonia  (Plexaura)  flexuosa,  Lamouroux. 

This  species,  of  which  we  obtained  several  specimens,  is,  I 
believe,  without  doubt  the  Gorgonia  angniculus  of  Dana  (U.  S. 
Exploring  Expedition,  Zoophytes,  p.  668).  It  is  referred  to 
under  Lamouroux's  name  as  a  member  of  the  Bermudian 
fauna  in  Dana's  "Corals  and  Coral  Islands,"  p.  114,  1872. 

Gorgonia  (Plexaura)  homomalla,  Esper. 
Gorgonia  (Plexaura)  multicauda,  Lam. 

Gorgonia  crassa,  Ellis  and  Solander. 

G.  vermiculata,  Edwards  and  Haime. 

The  exact  limitations  and  synonymy  of  this  species  are 
difficult  to  make  out,  but  as  far  as  my  studies  have  permitted 
me  to  analyze  the  forms  above  indicated  from  the  rather  in- 
sufficient or  deficient  descriptions  that  have  been  furnished  by 
their  authors,  they  appear  to  represent  an  identical  form. 
As  such  I  have  accordingly  referred  them  in  this  list. 

Gorgonia  (Plexaura)  dichotoma,  Esper. 

A  single  specimen,  measuring  about  a  foot  and  three-quar- 
ters in  height,  with  the  main  stems  somewhat  over  a  half-inch 
in  diameter. 

Gorgonia  (Eunicea)  pseudo-antipathes,  Lam. 

One  much  branched  specimen,  and  another,  slightly  differing, 
which  appears  to  belong  to  the  same  species. 

Pterogorgia  acerosa,  (?)  Pallas. 

A  single  specimen  of  a  large  Pterogorgia,  entirely  stripped 
of  coenenchyma,  and  measuring  about  two  and  a-half  feet  in 
height,  was  obtained  through  purchase  at  the  Crawl.  The 
axial  skeleton  is  yellowish,  or  of  the  color  of  earth.  The 
terete  branches  are  much  more  broadly  spreading  than  in  P. 
setosa,  and  unite  into  a  common  basal  stalk  which  is  upwards 
of  two  inches  in  thickness.  The  pinnules  are  very  numerous, 


ZOOLOGY  OF  THE  BERMUDAS.  105 

exceedingly  slender,  and  pendulous,  giving  to  the  whole 
organism  the  decided  appearance  of  a  weeping-willow. 

I  have  not  been  able  to  satisfy  myself  as  to  the  exact 
affinities  of  this  species.  It  appears  to  differ  broadly  from  the 
common  purple  sea-feather  of  the  West  Indies,  and  does  not 
have  the  depressed  branches  which  are  assumed  for  Esper's 
Pterogorgia  acerosa.  It  is,  however,  with  little  doubt  one  of  the 
forms  that  are  included  by  Pallas  in  his  Gorgonia  acerosa 
(Quercus  marina  Tlieophrasti),  and  may  be  the  one  that  is 
referred  to  by  Milne-Ed  wards  as  Pterogorgia  Sloanci. 

Of  the  species  of  gorgonians  above  enumerated  Dana  indi- 
cates Rhipidogorgia  flabellum,  Gorgonia  flexvosa,  G.  homomalla, 
and  G.  crassa  as  coming  from  the  Bermudas  ("  Corals  and 
Coral  Islands,"  p.  114).  I  find  no  mention  in  any  more  recent 
work  of  the  occurrence  there  of  either  Gorgonia  pseudo-anti- 
pathes  or  G.  dichotoma.  On  the  other  hand,  we  failed  to  obtain 
the  Pterogorgia  Americana  mentioned  by  Dana. 

ACTINIARIA. 

For  the  following  contribution  to  the  "  Actinology  of  the  Ber- 
mudas" I  am  indebted  to  Prof.  J.  Playfair  McMurrich,  who 
has  carefully  examined  and  studied  all  the  specimens  contained 
in  our  collection.  These  were  not  very  numerous,  but  still 
sufficiently  so  to  present  a  number  of  interesting  points  in 
special  morphology  and  geographical  distribution.  The  ob- 
servations here  recorded  have  appeared  in  advance  in  the  Pro- 
ceedings of  the  Academy  of  Natural  Sciences  of  Philadelphia. 

THE  ACTINOLOGY  OF  THE  BERMUDAS. 

BY 
PROF.  J.  PLAYFAIR  MCMURRICH. 

I  recently  received  from  Professor  Heilprin  a  number  of 
actinians  which  he  had  collected  in  the  summer  of  1888,  dur- 
ing a  visit  to  the  Bermuda  Islands.  They  were  entrusted  to 
me  for  identification  and  study,  and  I  gladly  availed  myself  of 


106  THE  BERMUDA  ISLANDS. 

the  opportunity  thus  afforded  of  comparing  the  actinian  fauna 
of  the  Bermudas  with  that  of  the  Bahamas,  which  I  had  pre- 
viously studied.*  I  may  state  here  that,  so  far  as  can  be 
judged  from  the  material  studied,  there  is  very  great  similarity 
between  the  two  faunas,  most  of  the  species  from  the  Bermudas 
occurring  also  either  in  the  Bahamas  or  in  the  West  Indian 
Islands.  Unfortunately,  it  was  impossible  to  adopt  the  best 
methods  of  preserving  the  material  obtained  in  the  Bermudas, 
the  expedition  to  the  islands  having  been  undertaken  mainly 
for  geological  purposes,  and  consequently  the  specific  relation- 
ships of  some  of  the  forms  could  not  be  determined  with  per- 
fect certainty. 

SAGARTID^J. 
Aiptasia.     sp?     (PI.  10,  figs.  1  and  2.) 

In  the  collection  were  four  specimens  of  a  form  which  I  re- 
t  fer  to  the  genus  Aiptasia,  inasmuch  as  in  the  majority  of 
respects  they  resemble  forms  of  that  genus,  although  it  was 
impossible  to  ascertain  the  presence  of  an  equatorial  row  of 
cinclides  owing  to  the  ectoderm  having  been  almost  completely 
macerated  away.  Nematocysts  were  quite  abundant  in  the 
macerated  substance  contained  in  the  inter-  and  intra-mesen- 
terial,  chambers,  but  it  was  not  possible  to  be  certain  that  they 
belonged  to  acontia,  though  such  was  probably  the  case. 

The  specimens  were  about  1  cm.  in  length  and  0.65  cm.  in 
diameter.  The  color,  as  ascertained  from  the  alcoholic  ma- 
terial, is  in  the  upper  one-third  of  the  column  and  in  the  ten- 
tacles grass-green,  while  the  rest  of  the  column  presents  the 
dirty  grayish-brown  color  frequent  in  alcoholic  specimens. 
About  one-third  of  the  way  down  the  column  each  specimen 
presents  a  well  marked  constriction,  below  which  the  column 
is  cylindrical,  while  above  it  gradually  expands,  the  disc  not 
being  at  all  infolded  in  contraction.  The  base  is  evidently 
adherent,  but  in  two  of  the  specimens  it  is  much  smaller  than 

*See  Journal  of  Morphology,  vol.  iii.     This  paper   is  now  in    print   and  will 
shortly  appear. 


ZOOLOGY  OF  THE  BERMUDAS.  107 

the  column,  and  is  almost  covered  by  the  infolding  of  the  column 
walls  over  it;  this  apparently,  however,  is  an  abnormal  condi- 
tion. The  column  is  smooth,  and  no  traces  of  cinclides  could 
be  seen  as  stated  above.  Sections  (PL  10,  fig.  2)  show  that 
the  mesogloea  is  thin  throughout,  and  that  the  circular  muscles 
(cm)  are  only  feebly  developed.  There  is  a  special  sphincter 
(sp)  imbedded  in  the  mesogloea,  immediately  below  the  margin, 
and,  though  not  very  powerful,  is  yet  quite  apparent.  The 
only  specks  of  Aiptasia  in  which  such  a  sphincter  has  been  ob- 
served as  yet  is  A.  pallid  a  of  our  Eastern  coast.  Immediately 
below  this  the  mesoglceal  muscular  processes  which  support 
the  circular  muscles  are  weak,  but  further  down  they  enlarge 
gradually  and  form  a  second  sphincter  (sp1)  similar  to  what 
has  been  described  by  E.  Hertwig*  in  Leiotealia  nymphcea.  It 
is  to  the  presence  of  this  lower  sphincter  that  the  contraction 
of  the  column  mentioned  above  is  due. 

The  tentacles  are  48  in  number  and  are  arranged  in  four 
cycles.  They  are  strongly  entacmseous,  and  are  not  infolded 
during  contraction.  Those  of  the  first  cycle  measure  1.1  cm., 
and  those  of  the  outermost  cycle  0.3  cm.  The  ectodermal  and 
endodermal  muscular  processes  are  present,  but  do  not  call  for 
a  special  description.  The  disc  is  flat  and  the  stomatoda3um  is 
without  well-marked  gonidial  angles;  sections  show  that  the 
grooves  are  hardly  developed. 

The  mesenteries  are  in  four  cycles.  The  six  pairs  of  the  first 
cycle  are  alone  perfect ;  those  of  the  second  cycle  are  shorter 
but  provided  with  wrell-developed  longitudinal  muscles,  while 
neither  those  of  the  third  nor  those  of  the  fourth  cycle 
have  the  longitudinal  muscles,  the  members  of  the  latter  cycle 
not  projecting  above  the  surface  of  the  endoderm.  The  parieto- 
basilar  muscles  seem  to  be  wanting,  or  at  least  have  no  marked 
mesoglceal  processes.  The  reproductive  organs  are  borne  by  the 
mesenteries  of  the  second  cycle,  and  also  by  those  of  the  first 
cycle  (except  by  the  directives)  below  the  internal  opening  of 

*R.  Hertwig — Report  on  the  Actiniaria.     Zoology  of  the  Voyage  of  II.  M.  S. 
Challenger.     Vol.  vi.     Pt   xv.  1882. 


108  THE  BERMUDA  ISLANDS. 

the  stomatodseum.  This  is  the  only  Sagartid,  with  the  excep- 
tion of  A.pallida,  in  which  I  have  observed  reproductive  organs 
on  the  mesenteries  of  the  first  cycle,  and  it  is  a  case  of  consider- 
able importance  inasmuch  as  it  necessitates  an  alteration  in 
the  definition  of  the  family  Sagartida3  as  given  by  R.  Hertwig.* 
One  of  the  essentials  of  the  family  is  that  "  the  principal  septa, 
or  septa  of  the  first  order,  only  are  perfect  and  at  the  same 
time  sterile."  The  last  portion  of  this  statement,  though  true 
for  the  majority  of  Sagartidaa,  fails  in  the  case  of  the  Aiptasiaa 
mentioned.  It  is  not  possible  t6  separate  Aiptasia  from  the 
Sagartidse ;  the  members  of  the  genus  possess  acontia,  cinclides, 
the  primary  mesenteries  alone  perfect,  and  a  mesodermal  mus- 
cle in  some  cases,  and  these  must  be  considered  as  the  chief 
characteristics  of  the  family. 

As  regards  the  species  to  which  the  form  under  consideration 
belongs,  the  probabilities  are  that  it  is  identical  with  A.pallida 
of  our  Eastern  coast,  since  in  its  anatomical  peculiarities  it 
agrees  very  closely  with  that  form.  The  impossibility  however 
of  ascertaining  the  coloration,  and  what  is  of  much  more  im- 
portance, the  occurrence  and  arrangement  of  the  cinclides, 
has  prevented  a  certain  identification,  and  I  have  preferred  to 
leave  the  species  in  doubt. 

ANTHEADJE. 
Condylactis  passiflora.     Duch.  and  Mich.     (Plate  10,  fig.  3.) 

Several  specimens  were  obtained  of  a  large  form,  measuring 
3.3-2.3  cm.  in  height  and  2.6-3.8  cm.  in  diameter  when  pre- 
served, which  resembled  in  coloration,  external  characters,  and 
for  the  most  part  in  internal  structure  also,  the  West  Indian 
form  Condylactis  passiflora.  In  the  alcoholic  specimens  the  col- 
umn is  of  a  brick-red  color  wherever  the  ectoderm  has  been 
preserved,  and  the  tentacles  are  grass-green,  this  color  evi- 
dently being  due  to  the  enormous  number  of  zooxanthelkc 
contained  in  the  endoderm.  Professor  Heilprin  informs  me  to 
the  best  of  his  recollection  the  tentacles  in  the  living  specimens 

*Loc.  cit. 


ZOOLOGY  OF  THE  BERMUDAS.  109 

were  as  a  rule  tipped  with  crimson.  In  a  separate  bottle  is  a 
single  specimen  evidently  identical  with  the  others,  and  accom- 
panying it  is  a  note  stating  that  the  column  was  red  and  the 
tentacles  brown.  This  specimen  was  found  freely  floating  near 
the  surface,  but  had  evidently  become  detached,  as  its  base 
shows  that  normally  it  is  an  attached  form. 

The  ectodern  having  been  macerated  away,  the  outer  surface 
of  the  mesogloea  is  exposed  to  view,  and  is  seen  to  be  divided 
by  fine  longitudinal  and  transverse  grooves  into  small  quad- 
rangular areas.  These  grooves  are  continued  over  the  limbus 
upon  the  surface  of  the  base,  the  longitudinal  grooves  there 
becoming  radiating  and  the  transverse  ones  concentric. 

The  only  character  which  is  markedly  different  from  what 
occurs  in  the  West  Indian  specimens  of  the  species  is  presented 
by  the  longitudinal  muscles  of  the  mesenteries.  The  middle 
portion  of  a  section  through  the  muscle-band  presents  an 
appearance  quite  similar  to  that  seen  in  the  West  Indian 
form,  and  the  internal  edge  is  also  the  same,  the  long  meso- 
gloeal  processes  terminating  abruptly,  and  being  followed  by 
smaller  processes  which  extend  to  the  commencement  of  the 
reproductive  region  of  the  mesentery ;  but  toward  the  inser- 
tion of  the  mesenteries  into  the  column  wall  the  arrangement 
is  slightly  different  (PI.  10,  fig.  3).  In  the  Bahama  specimens 
the  mesogloea  between  the  outer  edge  of  the  muscle-band  and 
the  insertion  of  the  mesentery  into  the  column  wall  is  thin, 
and  the  muscle-band  gradually  thins  out  externally.  In  the 
Bermuda  forms,  however,  the  longitudinal  muscle  begins  ab- 
ruptly, and  the  mesogloea  external  to  it  is  thick,  with  short, 
stout  muscle  processes;  or,  as  in  the  directives,  with  the 
muscle  cells,  instead  of  appearing  to  cover  processes,  present- 
ing rather  the  appearance  of  here  and  there  dipping  down 
slightly  into  the  mesogloaa. 

It  is  not  probable,  however,  that  this  slight  difference  is  to 
be  regarded  as  specific,  and  since  in  other  respects  there  is 
almost  exact  correspondence,  the  Bermuda  forms  must  be  con- 
sidered identical  with  those  from  the  Bahamas. 


110  THE  BERMUDA  ISLANDS. 

PHYLLACTIDJE. 

Some  points  of  considerable  importance  as  regards  the  char- 
acteristic structure  of  the  members  of  this  family  have  been  ob- 
tained from  the  study  of  the  two  forms  which  I  include  here 
within  it.  The  family  was  established  by  Andres*  for  forms  in 
which  the  disc  is  furnished  towards  the  center  with  simple 
tentacles  and  towards  the  periphery  with  foliaceous  fronds.  In 
one  of  the  forms  about  to  be  described  the  fronds  are  replaced 
by  short  digitiform  tentacles  arranged  in  a  single  cycle,  but 
nevertheless  it  agrees  in  other  structural  points  with  Oulactis, 
and  I  have  therefore  found  it  necessary  to  alter  the  definition 
of  the  family,  placing  importance  on  internal  anatomical 
structures  rather  than  upon  external  characteristics. 

In  the  first  place,  in  the  Oalactis  about  to  be  described,  and 
in  Diplactis,  as  I  propose  to  name  the  genus  to  which  the  form 
with  tentacles  replacing  the  fronds  will  be  referred,  a  sphinc- 
ter of  the  diffuse  type  is  present,  but  instead  of  being  situated 
upon  the  column  wall  below  the  margin,  it  occurs  internal  to 
the  margin,  between  the  inner  tentacles  and  the  peripheral 
fronds  or  tentacles.  In  0.  flosculifera  from  the  Bahamas  this 
sphincter  was  not  observed,  but  was  probably  overlooked  in 
the  single  specimen  I  obtained  for  study,  and  none  of  the  prep- 
arations which  I  still  possess  include  the  region  in  which  the 
sphincter  should  occur.  Secondly,  in  the  two  species  of 
Oulactis  which  I  have  studied,  and  in  the  Diplactis,  the  gonidial 
grooves  are  very  deep,  and  are  prolonged  a  considerable  dis- 
tance below  the  inner  margin  of  the  stomatodseum  ;  the  histo- 
logical  structure  also  of  the  ectoderm  lining  the  grooves  differs 
slightly  from  that  of  the  general  surface  of  the  stomatodeeum, 
it  is  not  thrown  into  folds  as  it  is  elsewhere,  and  the  mesogloea 
of  the  grooves  is  thickened. 

I  would  define  the  family  PhyllactidaB  as  follows : — Actininoe 
in  which  the  disc  is  furnished  with  simple  tentacles  towards 
the  center  and  with  a  cycle  of  short  digitiform  tentacles  or 

*A.   Andres.     Le   Attinie.     fauna   und  Flora   des   Golfes  von  Neapel,   Aluno- 
graphie  ix.  1883. 


ZOOLOGY  OF  THE  BERMUDAS.  Ill 

more  or  less  foliaceous  fronds  towards  the  periphery;  a  sphinc- 
ter of  the  diffuse  type  occurs  upon  the  inner  surface  of  the 
disc  between  the  inner  tentacles  and  the  outer  tentacles  or 
fronds ;  and  the  stomatodseum  is  provided  with  two  deep  goiiid- 
ial  grooves,  which  are  prolonged  some  distance  below  the 
inner  extremity  of  the  stomatodseum. 

The  family  Phyllactidse  was  placed  by  Andres  in  the  sub- 
order (family)  Stichodactylinse,  the  fronds  being  considered 
homologous  with  tentacles.  I  have  here  ventured  to  remove 
the  family  to  the  sub-order  Actininse,  and  it  will  be  necessary 
to  furnish  my  reasons  for  such  a  change.  The  tentacles  must 
necessarily  be  considered  outgrowths  of  the  disc,  since  struct- 
urally they  resemble  it  closely  while  differing  greatly  from 
the  column.  Are  the  fronds  also  disc  structures? 

The  question  turns  upon  what  we  shall  consider  to  be  the 
limit  between  the  disc  and  the  column.  The  majority  of 
authors  have  taken  a  more  or  less  distinct  fold  of  the  body 
wall,  the  margin,  frequently  furnished  with  conspicuous 
acrorhagi,  to  be  the  boundary,  and  certainly  in  many  cases 
there  seems  to  be  a  marked  difference  on  either  side  of  this 
fold.  Thus,  the  column  may,  as  in  Bunodes  and  Phymactis,  be 
turberculated  as  far  as  the  margin,  but  beyond  this  the  tuber- 
cles cease,  and  there  is  apparently  a  decided  difference  between 
the  region  below  and  that  above  the  limiting  fold. 

In  the  Sagartidse  and  Paractida3  there  is  imbedded  in  the 
column  wall  below  the  margin  a  sphincter  muscle.  In  other 
forms,  however,  such  as  the  Bunodidse,  which  possess  a  circum- 
scribed endodermal  sphincter,  that  structure  lies  internal  to  the 
margin.  If  we  assume  with  the  Hertwigs  that  the  sphincter 
is  a  columnar  structure,  its  situation  in  the  Bunodidse  would 
indicate  that  the  margin  is  not  the  boundary  between  the  disc 
and  column. 

Neither  the  margin  nor  the  sphincter,  however,  can  be  con- 
sidered the  morphological  boundary  of  the  disc,  since  both  seem 
to  vary  somewhat  in  position.  The  true  criterion  is  to  be  found 
iu  the  difference  of  histological  structure  presented  by  the  disc 


112  THE  BERMUDA  ISLANDS. 

and  column  ectoderm.  This  layer  in  the  disc  possesses  ecto- 
dermal  muscle-cells  and  a  nerve-layer,  which  structures  are 
absent  in  the  column.  The  tentacles  resembling  the  disc  in 
structure  are  to  be  considered  outgrowths  of  that  region,  and 
passing  outward  from  these  one  finds  that  the  characteristic 
structures  of  the  disc  gradually  fade  out  and  are  lost.  It  is 
impossible  to  say  just  where  the  change  is  completed,  but  the 
region  in  which  it  occurs  must  be  considered  the  boundary  be- 
tween the  disc  and  column.  In  Banodes  taeniatus  and  Aulactinia 
stelloides  I  find  that  the  sphincter  muscles  lie  beneath  the  outer 
border  of  this  indifferent  region,  and  are  consequently  to  be  re- 
garded as  columnar  structures. 

In  the  Phyllactidse  the  sphincter  muscle  lies  between  the 
tentacles  and  the  fronds,  and  although  the  ectoderm  in  the  re- 
gion in  which  it  occurred,  and  in  the  area  between  the  fronds 
or  their  representatives  and  the  margin  was  completely  mac- 
erated away  in  the  forms  studied,  yet  reasoning  from  the  rela- 
tions of  the  sphincter  in  other  forms  we  must  conclude  that  the 
region  between  the  margin  and  the  base  of  the  tentacles  is 
columnar,  and  that  the  fronds  and  outer  digitiform  tentacles 
are  column  structures,  perhaps  comparable  to  acrorhagi,  and 
cannot  be  considered  homologous  with  tentacles.  Accordingly, 
only  one  tentacle  belongs  to  each  intra-mesenterial  space,  and 
the  Phyllactidse  must  be  referred  to  the  sub-order  Actininse. 

Andres,  in  the  introduction  to  his  Monograph,  notes  the  fact 
that  the  margin  does  not  alwa}rs  mark  the  boundary  between 
the  disc  and  the  column.  He  proposes  the  term  "  collar  "  to 
denote  the  portion  of  the  column  internal  to  the  margin. 
Gosse's  term  "  fosse "  is  not  applicable  in  all  cases,  as  for  in- 
stance in  Condylactis,  where  the  region  does  not  form  a  depres- 
sion, but  is  horizontal. 

Oulactis  fasciculata.    n.  sp.     (PI.  10,  fig.  5.) 

By  this  name  I  denote  three  specimens  in  various  degrees  of 
contraction,  the  largest  of  which  measured  about  1  cm.  in 
height  and  1-2  cm.  in  breadth.  The  color,  as  ascertained  from 
alcoholic  specimens,  is  in  the  lower  part  of  the  column  a  gray- 


PULPIT   ROOK;   NORTH   SHORE. 


ZOOLOGY  OF  THE  BERMUDAS.  113 

ish-brown,  similar  to  what  is  frequently  seen  in  preserved 
ActininaD,  while  the  upper  part  of  the  column  and  the  fronds 
are  of  a  grass-green,  the  tentacles  resembling  somewhat  the 
lower  part  of  the  column,  but  having  a  distinctly  greenish  tinge. 

The  column  is  provided  in  its  upper  part  with  about  48  ver- 
tical series  of  tubercles,  probably  verruca3,  there  being  about 
five  or  six  in  each  series,  and  is  thrown  into  numerous  trans- 
verse folds,  the  result  of  contraction.  The  mesoglcea,  when 
exposed,  appears  to  be  raised  into  numerous  minute  elevations, 
whereby  the  surface  acquires  a  finely  punctured  appearance. 

The  tentacles  are  moderately  long,  simple  and  pointed  at  the 
extremity.  They  appear  to  be  arranged  in  two  cycles,  and 
from  a  necessarily  uncertain  count  I  estimate  their  number  to 
be  about  forty-eight.  Their  ectodermal  longitudinal  muscle 
layer  is  well  developed,  being  arranged  on  long  slender 
mesogloeal  processes.  The  fronds  (PI.  10,  fig.  5,  fr.)  are  small, 
yet  occupy  the  entire  width  of  the  area  between  the  tentacles 
and  the  apparent  margin.  They  consist  of  hollow  evagina- 
tions  of  the  disc,  arranged  in  bunches.  I  could  not  determine 
with  certainty  their  number  in  any  of  the  specimens,  but  there 
are  probably  twenty-four  of  them  in  all.  A  well-defined  mar- 
gin is  present. 

Immediately  external  to  the  bases  of  the  tentacles,  and  lying 
between  them  and  the  fronds  there  is  an  endodermal  sphincter 
(sp)  fairly  well  developed.  Immediately  external  to  it,  in  the 
region  occupied  by  the  fronds,  and  for  a  slight  distance  down 
the  column-wall  below  the  margin,  there  are  no  muscle  proc- 
esses, but  further  down  they  do  occur,  forming  what  might  be 
termed  a  second  sphincter,  though  it  is  by  no  means  well 
developed.  The  surface  of  the  disc  between  the  tentacles  and 
the  mouth  is  deeply  depressed,  so  that  a  fosse  is  formed  around 
the  peristome.  The  mouth  is  large.  Sections  show  that  over 
the  general  surface  of  the  stomatodamm  the  mesoglcea  is  very 
thin,  and  upon  the  ectodermal  surface  gives  rise  to  numerous 
more  or  less  regularly  arranged  fine  processes,  over  which  the 
ectoderm  passes  so  as  to  be  thrown  into  numerous  folds.  The 


114  THE  BERMUDA  ISLANDS. 

gonidial  grooves  are  deep,  and  are  prolonged  some  distance 
below  the  rest  of  the  stomatoda3um.  Its  mesogloea  is  much 
thickened,  and  is  devoid  of  processes  upon  its  ectodermal  sur- 
face, being  thus  strongly  contrasted  with  that  of  the  stomato- 
dseum.  In  its  histology  the  ectoderm  of  the  groove  also  differs 
from  that  of  the  general  stomatoda3um,  the  glandular  cells 
being  evidently  fewer  in  number,  but  the  preservation  of  the 
specimens  was  not  sufficiently  perfect  to  permit  the  details  to 
be  made  out. 

There  are  altogether  twenty-four  pairs  of  mesenteries,  twelve 
of  which  are  perfect.  The  six  primary  pairs  are  united  with 
the  stomatodseum  to  a  greater  extent  than  are  the  six  secon- 
daries, and  the  two  pairs  of  directives  have  a  much  more  ex- 
tensive union  than  any  of  the  other  primary  mesenteries, 
owing  to  the  great  prolongation  of  the  gonidial  grooves.  The 
longitudinal  muscle  processes  form  a  strongly  projecting 
though  rather  narrow  band,  the  edges  of  which  are  sharply 
defined,  the  processes  being  of  equal  length  throughout  the 
muscular  area,  and  diminishing  abruptly  towards  the  sides. 
The  mesoglcea  of  the  portion  of  the  mesenteries  external  to 
the  muscle  bands  is  rather  thick,  and  there  is  a  strong  parieto- 
basilar  muscle.  Apparently  only  the  mesenteries  of  the  third 
cycle,  i.e.  the  imperfect  mesenteries,  are  gonophoric,  but  my 
preparations  do  not  allow  of  certainty  on  this  point. 

A  few  remarks  are  called  for  concerning  the  relationship  of 
this  species.  I  was  at  first  tempted  to  identify  it  with  0. 
/ormosa,*  but  further  consideration  led  me  to  separate  it  as  a  new 
species.  The  fronds  differ  markedly  from  those  of  other 
species  of  Oulactis.  In  these  they  have  been  described  as 
being  "  ddcoraces"  a  term  which  cannot  be  applied  to  the 
fronds  of  0.  fasciculata.  In  it  they  consist  of  bunches  of  finger 
or  club-shaped  hollow  processes,  the  various  processes  of  each 
bunch  being  united  by  their  base  but  distinct  above.  This 
arrangement  suggested  the  specific  term  which  I  have  em- 

*Duchassaing   and    Micheloiti — Mem.   Keale  Accademia   di     Torino.      2nd    Ser. 
xix,  1860,  and  xxiii,  1806. 


ZOOLOGY  OF  THE  BERMUDAS.  115 

ployed,  and  I  think  is  of  sufficient  importance  to  warrant  the 
formation  of  a  new  species.  It  was  a  question  whether  a  new 
genus  should  be  instituted,  as  Verrill1  has  done  in  the  case  of 
Lophactis  ornata,  but  there  is  such  close  agreement  with  the 
Bahaman  O.flosculifera  as  regards  the  internal  structure,  the 
number  of  perfect  mesenteries,  and  the  distribution  upon  the 
mesenteries  of  the  reproductive  organs,  that  such  a  proceeding 
was  considered  unnecessary.  It  seems  probable  that  the  genus 
Lophactis  should  be  fused  with  Oulactis. 

DIPLACTIS.  Gen.  nov. 

I  propose  this  generic  name  for  two  species,  one  of  which  is 
described  below,  which  do  not  seem  to  be  referable  to  any  of 
the  genera  now  recognized.  The  genus  may  be  briefly  defined 
as  follows: — Phyllactidse  in  which  the  fronds  are  represented 
by  a  single  cycle  of  short  digitiform  tentacles  and  in  which  all 
the  mesenteries  except  those  of  the  first  cycle  are  gonophoric. 
The  term  Diplactis  has  been  chosen  as  indicating  the  tentacular 
appearance  of  the  fronds,  from  which  it  seems  as  if  there 
were  two  series  of  tentacles,  an  inner  and  an  outer  (diplous, 
double,  and  aklis,  a  ray). 

In  the  Supplementary  Report  on  the  Actiniaria  collected  by 
the  "  Challenger,"  R.  Hertwig  decribes  a  form  whose  locality 
is  unknown,  which  lie  refers  to  Gosse's  genus  HormatJiia.  It  is 
very  similar  to  the  form  about  to  be  described  from  the  Ber- 
mudas, and  there  can  be  no  doubt  that  though  specifically 
distinct  the  two  must  be  referred  to  the  same  genus.  Gosse's 
Hormathia?  was  described  from  a  single  specimen  brought  up 
on  a  deep-sea  fishing  line,  and  attached  to  the  shell  of  a  living 
Fusus.  It  was  characterized  by  possessing  slightly  below  the 
margin  about  ten  spherical  protrusions.  I  do  not  think  it  is 
possible  to  associate  in  the  same  genus  with  this  either  the 
Bermuda  Diplactis  or  Hertwig's  Hormathia.  In  the  first  place 
in  both  these  forms  the  bodies  near  the  margin  are  digitiform 
and  not  spherical ;  and  secondly,  these  bodies  are  situated  not 

1  Verrill,— Trans.  Conn.  Aca<l.     Vol.  i,  1808. 

2  P.  H.  Gosse.     "  Aclinologia  Britannica."     London.     1860. 


116  THE  BERM.UDA  ISLANDS. 

below  the  margin,  but  internal  to  it.  In  all  the  Bermuda  speci- 
mens, of  which  there  are  quite  a  large  number,  a  well-marked 
margin  is  present  and  Hertwig  describes  in  his  form  a  fold  of  the 
column-wall  which  must  be  considered  equivalent  to  the  mar- 
gin of  the  other  species.  Although  the  margin  cannot  be  con- 
sidered of  importance  as  marking  the  boundary  of  the  disc, 
yet  it  is  a  structure  of  frequent  occurrence  and  must  be  taken 
account  of.  Structures  that  occur  on  the  column-wall  below 
it,  as  in  Hormathia,  cannot  be  considered  identical  for  syste- 
matic purposes  with  others  which  invariably  lie  above  or 
internal  to  it,  and  are  not  quite  similar  in  form. 

It  must  be  noticed  that  Haddon  has  recently  referred  to 
Gosse's  Hormathia  a  form*  altogether  different  from  that  as- 
signed to  it  by  Hertwig.  The  correctness  of  Haddon's  iden- 
tification is  quite  as  doubtful  as  Hertwig's,  if  not  a  little  more 
so.  The  form  is  certainly  a  Sagartid,  and  probably  a  Pltellia, 
it  being  stated  that  it  is  very  similar  to  Hertwig's  Phellia 
pedinata. 

Hertwig  refers  his  Diplactis  (HormatJiia)  delicatula  to  the  fam- 
ily Antheadsc,  on  account  of  the  diffuse  endodermal  nature  of 
sphincter.  The  situation  of  the  mus?le  and  other  characters 
make  it  evident  that  Diplactis  should  be  associated  in  the  same 
family  with  Ouladis.  In  the  Phyllactidse  as  here  limited  we 
have  several  grades  of  complication  of  the  fronds.  In  Diplactis 
their  structure  is  exceedingly  simple,  being  simply  digitiform 
in  D.  Bermudensis  and  club-shaped  in  D.  delicatula.  In  O.fasci- 
culata  they  are  somewhat  more  complicated,  and  from  this  the 
passage  is  easy  to  Verrill's  0.  (Lopliadis)  ornata,  and  from  this 
to  the  very  complicated  structure  seen  in  0.  flosculi/era. 

Diplactis  Bermudensis.     n.  sp.     (PI.  10,  figs.  4  and  6,  PI.  11,  figs.  1  and  2.) 

A  number  of  specimens  of  the  form  for  which  I  propose  this 
name  were  obtained.  The  majority  were  in  a  partially  con- 
tracted condition,  but  apparently  the  power  of  contraction  is 
not  fully  developed,  as  in  none  were  the  tentacles  completely 

*  A.  C.  Haddon  — On  two  species  of  Actiniae  from  the  Mergui  Archipelago. — 
Journ.  Linn.  Soc.     Vol.  XXI.     1888. 


ZOOLOGY  OF  THE  BERMUDAS.  117 

concealed.  The  average  height  of  the  specimens  is  about  1/5 
cm.  and  the  breadth  nearly  the  same,  and  thus  D.  Bermudensis 
is  decidedly  smaller  than  D.  dclicatula.  The  ectoderm  has  been 
almost  entirely  macerated  away,  so  that  the  external  surface  of 
the  rncsogloea  is  exposed  to  view.  This  presents  numerous 
transverse  folds  due  to  contraction,  but  in  addition  fine  linear 
depressed  stria?  are  present,  both  horizontal  and  longitudinal, 
dividing  the  surface  into  numerous  rows  of  small  quadrangu- 
lar elevations  visible  to  the  unaided  eye.  The  color  through- 
out is  a  dirty-green. 

The  base  is  adherent,  flat,  and  about  the  same  size  as  the 
column.  It  is  marked  by  radiating  and  concentric  striaB,  con- 
tinuations of  the  longitudinal  and  horizontal  stria?  respectively 
of  the  column.  No  verruca)  or  tubercles  occur  on  the  column, 
though  the  quadrangular  areas  produced  by  the  striae  are 
slightly  more  prominent  toward  the  margin.  This  is  well 
marked  and  smooth,  and  is  separated  from  the  tentacles  by  a 
deep  fosse  (collar),  near  the  bottom  of  which  are  about  12  short 
digitiform  fronds  about  1  mm.  in  height.  (PI.  10,  fig.  4p,  and 

PI.  11,  fig.  i.) 

Between  these  fronds  and  the  tentacles  there  is  upon  the 
endodermal  surface  of  the  collar  a  sphincter  (PL  10,  fig.  4,  sp) 
of  the  diffuse  type,  which  differs  markedly  from  that  of  D. 
delicatula,  the  mesogloeal  processes  being  much  more  delicate, 
and  anastomosing  somewhat  in  their  proximal  portions  (PI. 
11,  fig.  2).  The  circular  muscles  of  the  column  wall  external 
to  the  digitiform  fronds  are  fairly  prominent,  and  are  con- 
tinued the  entire  way  down  the  column,  not  enlarging  however 
to  form  a  second  sphincter. 

The  tentacles  are  simple,  conical,  and  of  moderate  length, 
and  are  arranged  in  four  cycles,  their  number  being  probably 
96.  By  actual  count  they  seemed  to  vary  somewhat,  usually 
falling  below  that  number,  but  the  discrepancies  are  probably 
due  to  the  difficulty  of  making  a  correct  enumeration.  They 
possess  well-developed  mesoglceal  processes  for  the  support 
of  the  ectoderwal  muscles,  The  disc  is  deeply  folded  in,  in- 


118  THE  BERMUDA  ISLANDS. 

ternal  to  the  tentacles,  so  as  to  form  a  deep  fosse  around  the 
peristome  (PL  11,  fig.  1),  which,  however,  does  not  rise  above 
the  level  of  the  margin.  I  was  not  able  to  distinguish  in  any 
of  my  preparations  the  delicate  mesogloeal  processes  of  the  disc 
which  support  the  ectodermal  muscle  cells  in  D.  delicotula,  but 
it  is  possible  that  they  had  been  macerated  away. 

The  mesogloea  of  the  stomatodseum  is  raised  upon  its  ecto- 
dermal surface  into  prominent  but  rather  delicate  ridges,  over 
which  the  ectoderm  is  folded.  The  gonidial  grooves  are  deep, 
and  as  in  Ouladis  are  prolonged  below  the  level  of  the  internal 
opening  of  the  stomatodaeum,  and  have  the  mesogloea  thick- 
ened. In  D.  delicatula  Hertwig  describes  the  gonidial  grooves 
as  being  hardly  marked  in  the  stomatodseum,  and  if  this  is 
found  to  be  an  invariable  characteristic,  it  will  be  necessary  to 
alter  slightly  the  definition  of  the  Phyllactida3  given  above. 
The  depth  of  the  grooves,  and  their  prolongation  downwards, 
are  so  marked  in  the  other  members  of  the  group  that  I  have 
examined,  as  to  suggest  that  the  apparent  shallowness  in  the 
specimen  examined  by  Hertwig  may  be  due  to  distortion. 

The  primary  and  secondary  mesenteries  are  perfect  through- 
out the  whole  length  of  the  stomatodseum ;  the  tertiaries  are 
perfect  in  their  upper  part,  but  lower  down  separate  from  the 
stomatodacum ;  while  the  fourth  cycle  consists  entirely  of  im- 
perfect mesenteries.  The  directives  are  attached  throughout 
a  greater  part  of  their  length  than  are  any  of  the  other  mesen- 
teries, owing  to  the  prolongation  of  the  gonidial  grooves.  The 
longitudinal  muscles  in  the  upper  portion  of  the  mesenteries 
form  a  low  band,  covering  the  greater  portion  of  thenon-gono- 
phoric  region  of  the  mesentery  ;  internally  the  muscle  processes 
end  rather  abruptly,  but  externally  they  gradually  diminish 
in  size.  In  the  lower  part  of  the  mesentery,  below  the  level  of 
the  stomatodacum,  the  arrangement  of  the  muscle  processes  is 
very  different  (PL  10,  fig.  6).  Throughout  the  greater  portion 
of  the  non-gonophoric  region  of  the  mesentery  they  are  very 
small,  but  as  the  gonophoric  region  is  approached  they  sud- 
denly increase  in  size,  forming  a  strong  projection,  and  then 


ZOOLOGY  OF  THE  BERMUDAS.  119 

just  as  suddenly  diminish  again,  the  projection  being  of  slight 
extent.  The  parieto-basilar  muscles  are  well  developed  and 
form  conspicuous  folds.  Both  external  and  internal  mesen- 
terial  stomata  are  present  (PI.  II,  fig.  1).  All  the  mesenteries 
with  the  exception  of  those  of  the  first  cycle  are  gonophoric. 

The  differences  between  D.  Bermudensis  and  D.  delicatula 
may  be  briefly  enumerated  as  follows: 

I).  Bermudensis.  D.  Delicatula. 

Tentacles  96.  Tentacles  160. 

Fronds  digitiform,  about  12  in     Fronds    dilated    at   the   ex- 
number,  tremity,  about  42  in  number. 
Mesogloeal  processes  of  sphinc-     Mesogloeal   processes    of 
ter  muscle  rather  delicate,  sphincter  stout,  not  anas- 
anastomosing  slightly.                     tomosing. 
Ectoderm al  muscle  processes  of    Ectodermal  muscle  processes 
disc  wanting  (?)                        of  disc  long  and  delicate. 

PHYMANTHID.ZE. 

Phymanthus  crucifer.     (Les.)  Andres. 

A  single  specimen  of  this  species  was  obtained.  I  have 
nothing  to  add  to  the  statements  already  made  regarding  it  in 
my  paper  on  the  Bahama  Actiniaria. 

ZOANTHID^B. 

Zoanthus  flos-marinus.     Duch.  and  Mich.     (PI.  11,  figs.  3  and  4.) 

A  large  number  of  specimens  of  this  species  were  obtained, 
and  inclosed  with  them  was  a  label  stating  that  they  were  col- 
lected at  Shelly  Bay  and  Tucker's  Town.  In  general  appearance 
they  resemble  Z.  sociatus  from  the  Bahamas,  the  individuals  as 
in  that  species  forming  stolon-like  prolongations  from  which 
new  individuals  bud  ;  their  structure,  however,  shows  them  to 
belong  to  a  different  species.  The  colonies  are,  according  to 
the  accompanying  label,  4  to  5  cm.  in  breadth.  The  indi- 
vidual polyps  in  the  preserved  condition  measure  1-2  cm.  in 
height,  and  in  breadth  at  the  upper  end  0-5  cm.  the  lower 
portion  and  stolons  measuring  about  0.25  cm.  All  are  strongly 
contracted,  a  small  depression  being  the  only  indication  of 


120  THE  BERMUDA  ISLANDS. 

where  the  entrance  into  the  interior  is  situated.  The  color, 
according  to  the  inclosed  label,  was  "spinach  -green,"  but  this 
must  be  taken  as  applying  ouly  to  the  upper  part  of  the 
column,  the  lower  part  and  the  stolons  being  brown  or  sand- 
colored.  The  disc  was  "  apple-green,"  and  the  tentacles  green. 

The  column  upon  the  outside  is  covered  by  a  cuticle,  in 
which  are  sparingly  imbedded  foreign  bodies.'  The  ectoderm 
is  separated  from  the  cuticle  by  a  layer  of  mesoglcea,  and  con- 
sists of  cells  arranged  in  groups  separated  by  partitions  of 
mesogloea,  but  not  showing  the  degeneration  which  occurs  in 
Z.  sociatus.  The  mesogloea  is  comparatively  thick,  and  consists 
of  a  homogeneous  matrix  containing  (1)  numerous  anastomos- 
ing spaces  more  or  less  filled  with  cells,  and  (2)  granular  cells 
which  give  rise  to  delicate  processes  which  enter  into  connec- 
tion with  other  granular  cells,  and  with  the  spaces  just  men- 
tioned, and  with  the  ectoderm  and  the  endoderm.  Some  sug- 
gestions regarding  the  origin  and  function  of  these  structures 
will  be  found  in  connection  with  the  description  of  M.  tuber- 
culata  which  follows.  The  endoderm  of  the  column  is  low, 
and  consists  of  more  or  less  spherical  cells,  usually  containing 
zooxanthellce.  A  delicate  layer  of  muscle  fibres  arranged  cir- 
cularly occurs  between  the  endoderm  and  the  mesogloea. 

At  the  upper  part  of  the  column  a  well-developed  double 
sphincter  muscle  occurs,  imbedded  in  the  mesogloea.  It  is 
stronger  than  that  found  in  Z.  sociatus,  and  more  nearly 
resembles  that  described  by  Erdmaim1  and-  Hertwig2  in  Z. 


The  tentacles,  according  to  the  brief  notes  taken  of  the  liv- 
ing specimens,  are  "  short,  50-60  in  number,  in  three  rows."  My 
preparations,  however,  show  that  the  last  statement  is  erro- 
neous, the  tentacles  being  arranged  in  two  cycles  only.  Their 
ectoderm  is  not  imbedded  in  the  niesogioaa,  nor  is  there  a 
cuticle  covering  it.  The  ectodermal  muscle  processes  of  the 

1  A.  Erdmann.      Ueber  einigc  neue  Zoantheeu.     Jen.  Zeit.  XIX.     1885. 

2  R.  Hertwig.     Supplement  to  report  on  the  Acliniaria.     Zoology  of  the  Voyage, 
of  H.  M   S.  Challenger.     Vol.  XXVI.     1888. 


ZOOLOGY  OF  THE  BEBMUDAS.  121 

mesoglcea  are  fairly  developed,  and  immediately  below  them 
are  to  be  seen,  imbedded  in  tbe  mesoglcea,  peculiar  granular 
pale  yellowish-green  cells,  the  protoplasm  of  which,  with  the 
exception  of  the  nucleus,  does  not  stain  with  carmine.  Other- 
wise the  mesogloea  is  homogeneous.  The  endoderm  is  thick, 
and  is  richly  supplied  with  zooxanthellrc.  In  structure  the 
disc  resembles  the  tentacles,  possessing,  like  them,  the  peculiar 
yellowish-green  granular  cells. 

The  mesogloea  of  the  stoinatod&um  is  homogeneous.  I  can- 
not make  any  statements  as  to  the  histology  of  the  ectoderm  of 
this  region,  as  it  had  macerated  into  a  mass  of  a  characteristic 
appearance  which  cannot  easily  be  described.  Transverse  sec- 
tions show7  that  the  gonidial  groove,  to  which  the  macro  or 
ventral  directives  are  attached,  is  very  shallow,  and  indeed  can 
hardly  be  said  to  exist. 

The  mesenteries  are  arranged  on  the  microtypus.*  Their 
mesogloea  is  for  the  most  part  very  thin  but  thickens  towards 
the  base  where  it  contains  a  canal.  (PL  11,  fig.  4,  be.)  A 
second  canal,  circular  in  section  and  packed  with  cells,  occurs 
in  the  thin  region,  the  mesogloea  splitting  to  form  its  walls. 
The  muscle  layers  are  only  slightly  developed. 

A  very  peculiar  arrangement  occurs  in  connection  with  the 
meseriterial  filaments  of  the  perfect  mesenteries.  Immediately 
below  the  stomatodaaum  the  mesenterial  filament  is  triradiate 
(PI.  11,  fig.  3),  the  central  ray  being  short  and  stout,  the  lateral 
rays  longer  and  recurved.  The  epithelium  covering  the  cen- 
tral ray  and  that  face  of  the  lateral  rays  which  looks  towards 
it  resembles  in  structure  that  of  the  stomatodrcum.  The  outer 
surface  of  the  lateral  rays  is,  however,  covered  with  cells  similar 
to  those  which  line  the  general  surface  of  the  mesentery.  In  a 
section  which  passes  through  the  stomatodaaum  a  little  above 
its  extremity,  the  intervals  between  the  perfect  mesenteries  is 
occupied  by  macerated  tissue  resembling  the  ectoderm  of  the 
stomatodaium.  Apparently,  it  lines  the  surfaces  of  the  mesen- 

*  See  Erdmann,  loc.  cit. 


122  THE  BERMUDA  ISLANDS. 

teries  for  a  short  distance  outwards  from  their  point  of  attach- 
ment to  the  stomatodamm,  and  also  the  outer  surface  of  the  lat- 
ter for  a  short  distance  above  its  inner  opening.  It  looks  as  if 
the  ectoderm  of  the  stomatodaaum  were  reflected  upwards,  so  as 
to  cover  its  endodermal  surface  and  the  adjacent  surfaces  of 
the  perfect  mesenteries.  Further  down  (PI.  11,  fig.  4)  the  two 
lateral  processes  of  the  mesenterial  filaments  disappear,  the  cen- 
tral one  alone  persisting.  It  is  evidently  the  "  glandular  streak  " 
of  the  filament.  The  cells  which  cover  the  surface  of  the  mes- 
entery for  some  distance  outward  from  this  towards  the  column- 
wall  are  very  peculiar.  (PL  11,  fig.  4di.)  They  form  a  layer 
much  thicker  than  that  formed  by  the  ordinary  endodermal 
colls,  and  are  loaded  with  green  granules,  closely  packed 
together  so  that  to  the  naked  eye  the  region  occupied  by  this 
layer  is  of  that  color.  Foreign  bodies  of  organic  nature  are 
imbedded  in  the  cells,  sometimes  being  surrounded  by  a  num- 
ber of  cells  containing  no  granules,  or  occasionally  imbedded 
in  the  mesogloea. 

In  unstained  specimens,  when  the  animal  is  laid  open  by  a 
longitudinal  incision,  this  region  of  the  mesenteries  is  very 
distinct  on  account  of  its  rich  green  color.  When  the  loose 
cells  of  the  green  area  are  scraped  away  with  a  scalpel  and 
examined,  they  are  seen  to  be  of  a  very  irregular  shape  (sug- 
gesting a  power  of  amoeboid  movement),  and  to  contain  nu- 
merous green  globules,  much  smaller  than  the  zooxanthellse^ 
darker  in  color,  and  homogeneous  in  structure.  Amongst  the 
cells  are  numerous  zooxanthellaa,  and  there  are  also  numerous 
spherical  refractive  bodies,  apparently  of  a  fatty  nature  and 
with  a  slightly-greenish  tinge,  as  well  as  the  foreign  bodies 
already  mentioned  as  seen  in  the  section,  and  very  numerous 
delicate  acicular  silicious  spicules. 

The  occurrence  of  these  spicules  and  organic  foreign  bodies 
in  the  cells  of  this  region  is  very  strong  evidence  in  favor  of 
the  supposition  that  they  have  a  digestive  function.  The 
green  globules  may  be  the  products  of  digestion.  If  this  be 
the  case  it  is  exceedingly  interesting,  as  indicating  a  method  of 


ZOOLOGY  OF  THE  BERMUDAS.  123 

digestion  in  the  Zoantheae  somewhat  different  from  what  is 
usually  described  as  occurring  in  the  rest  of  .the  Actiniaria. 

None  of  the  specimens  examined  possessed  sexual  organs. 
There  were  about  24-26  pairs  of  mesenteries  in  the  specimens 
examined. 

I  have  identified  this  form  with  Z.flos-marinus  of  Duchassaing 
and  Michelotti,  with  the  imperfect  description  of  wrhich  it 
agrees  fairly  well.  In  many  respects  it  comes  near  Z.  sociatus, 
but  differs  markedly  from  it  in  others;  such  for  instance,  as  in 
the  nature  of  the  ectoderm  and  in  the  form  of  the  sphincter- 
muscle,  so  that  it  must  be  regarded  as  distinct.  From  the 
only  Zoanthus  hitherto  described  from  the  Bermudas,  Z. 
Dante  (?)  of  Hertwig1  it  is  readily  distinguished  by  the  ab- 
sence of  any  distinct  line  of  demarcation  between  the  upper 
and  lower  portions  of  the  column. 

Mammillifera  tuberculata  (Gray)  (PI.  11,  figs.  5  and  6.) 

Isaurus  tuberculatus — J.  E.  Gray.     1828. 
Zoanthus  tuberculatus — Duchassaing  and  Michelotti.     1860. 
Antinedia  tuberculata — Duchassaing  and  Michelotti.     1866. 
Zoanthus  (MonantJius)  tuberculatus — Andres.     1883. 
Antinedia  Duchassaingi — Andres.     1883. 

This  form  was  first  described  by  J.  E.  Gray,2  from  specimens 
in  the  British  Museum  whose  locality  was  unknown.  He 
adopted  for  the  genus  Savigny's  name  Isaurus.  In  1860, 
Duchassaing  and  Michelotti  rediscovered  it,  and,  though  ap- 
parently unacquainted  with  the  earlier  description  of  Gray, 
applied  to  it  the  same  specific  name,  but  placed  it  in  the  genus 
Zoanthus,  on  account  of  the  absence  of  sandy  incrustations  on 
the  column  walls.  In  their  second  paper  these  authors,  placing 
importance  on  the  tuberculation  of  the  column  wralls,  erected 
for  its  reception  the  genus  Antinedia.  Andres,  in  his  most  use- 
ful monograph,  has  assumed  that  the  form  described  by  Gray 

1  R.  Hertwig.     Supplement  to  report  on  the  Actiniaria  of  the  Challenger  Expe- 
dition.    1888. 

2  J.  E.  Gray— "  Spicilegia  Zoologica."     London.     1828. 


124  THE  BERMUDA  ISLANDS. 

is  different  from  that  which  Duchassaing  and  Michelotti  ob- 
tained at  St.  Thomas  and  Guadeloupe,  relying  probably  on 
the  discrepancies  between  the  poor  figures  given  by  the  latter 
authors  and  the  more  correct  one  which  Gray  has  given.  He 
consequently  retains  the  specific  term  tuberculatus  for  Gray's 
form,  proposing  for  Duchassaing  and  Michelotti's  the  name 
Duchassaingi.  There  is  little  room  for  doubt,  however,  that 
the  two  forms  are  identical;  my  observations  have  shown 
that  the  species  is  to  be  referred  to  the  genus  Mammillifera  as 
defined  by  Erdmann. 

The  specimens  from  the  Bermudas  were  either  solitary, 
attached  to  a  piece  of  rock  by  a  base  only  very  slightly  ex- 
panded, or  else  were  grouped  together  in  twos  or  threes,  in 
which  case  they  were  united  by  a  slightly-developed,  flat  or 
slightly  tubular  coenenchyma.  In  none  had  the  ccenenchyma 
any  such  tubular  or  stolon-like  form  as  is  shown  in  the  figure 
given  by  Duchassaing  and  Michelotti.  Judging  from  the  speci- 
mens I  studied,  the  tendency  to  form  a  cosnenchyma  is  slight. 

The  polyps  (PI.  11,  fig.  5)  vary  in  height  from  1.3-2.7  cm.; 
their  diameter  being  about  0.7-0.9  cm.  The  column  is  marked 
by  six  or  eight  distinct  annular  grooves,  and  by  from  twenty 
to  twenty-five  longitudinal  ones.  In  the  lower  part  of  the 
column  the  ridges  formed  by  these  longitudinal  grooves  are 
entire,  but  higher  up  they  begin  to  be  divided  into  series  of 
tubercles,  a  row  of  these  corresponding  to  each  ridge.  These 
tubercles  increase  in  size  towards  the  margin  and  several 
become  grouped  together  upon  elevations  of  the  column  wall, 
giving  rise  to  mulberry-like  protuberances.  Near  the  margin 
the  tubercles  suddenly  cease,  forming,  in  contracted  specimens, 
a  strong  ridge  bounding  the  dome-shaped  area  which  forms  in 
such  specimens  the  summit.  This  dome-shaped  area  belongs 
to  the  column,  the  animal  being  strongly  contracted,  and 
though  without  tubercles  shows  clearly  the  continuation  up- 
wards upon  it  of  the  longitudinal  furrows,  and  is,  accordingly, 
marked  by  a  series  of  radiating  ridges. 

In  structure  the  tubercles  of  the  column  are  solid,  being 


ZOOLOGY  OF  THE  BERMUDAS.  125 

elevations  of  the  mesogloea.  This  tissue  throughout  the 
column  is  very  thick,  measuring  on  the  average  1  mm.  in 
thickness.  It  presents  numerous  anastomosing  canals  filled 
with  cells,  as  well  as  the  delicate  canals  which  have  been  de- 
scribed by  Erdmann  and  others,  very  distinctly.  These  canals 
are  without  doubt  processes  from  the  large  canals,  and  the 
structure  of  the  zoaiithan  mesogloea  may  be  compared  to  that 
of  a  bone,  such  as  a  frog's  femur,  the  anastomosing  canals 
being  compared  to  the  lacuna,  and  the  delicate  canals  to  the 
canaliculi.  My  preparations  of  M.  tuberculata  seem  to  show 
that  the  lacunae  arise  from  both  the  ectoderm  and  the  en  do- 
derm.  In  some  of  my  sections  deep  bays  can  be  seen  running 
from  the  endoderm  up  into  the  mesogloea,  and  from  their  ends 
and  sides  numerous  canaliculi  can  be  seen  branching  out. 
These  bays  are  found  in  various  stages  of  enclosure  by  the 
mesogloea,  the  cells  which  they  contain  being  in  some  cases 
continuous  with  the  general  endoderm,  in  other  cases  almost 
separated  from  it,  and  finally  quite  so.  So  too  with  the  ecto- 
derm. The  lacuna}  which  have  just  been  formed  in  this  man- 
ner are  much  larger  than  the  majority  of  those  scattered 
through  the  mesogloea,  these  frequently  consisting  of  only  a 
few  cells  or  even  a  single  cell,  and  further,  the  newly-formed 
lacunse  usually  contain  zooxanthelke,  which  are  rare  in  the 
older  ones.  It  would  seem  as  if  many  of  the  newly-formed 
lacuna  become  divided  into  smaller  portions  which  separate 
from  each  other,  except  by  the  delicate  canaliculi,  and  at  the 
same  time  undergo  an  alteration  in  the  histological  structure 
of  their  cells,  the  zooxanthellre  disappearing,  and  the  cells  be- 
coming filled  with  refractive,  deeply-staining  granules.  It 
seems  not  improbable  that  these  altered  cells  are  concerned  in 
the  formation  of  the  mesogloea,  their  granules  being  particles 
which  will  later  on  be  added  to  the  matrix  of  the  mesogloea. 

Upon  the  outside  of  the  column  is  a  thin  cuticle  (PL  11,  fig. 
6,  cu)  similar  to  what  occurs  in  Z.  sociatus  and  Z.  flos-marinus. 
Andres*  considers  this  to  be  merely  a  differentiation  or  hard-. 

*  A.  Andres.     On  a  new  genus  and  specie^  ol  Zoamhina  iM.ilacoilennata  (Pan 
ceria  s/>ongiosa,  sp.  n.) — Quart.  Journ.   Micros.  Sci.     N.  S.  Vol  xvii.     1887. 


126  THE  BERMUDA  ISLANDS. 

ening  of  the  external  layers  of  the  mesogloea,  but  I  cannot 
agree  with  this  view.  It  is  a  clearly  defined  layer  external  to 
the  mesogloea,  and  appears  quite  different  in  composition  and 
behavior  to  staining  fluids  from  that  tissue.  Below  this  cuticle 
comes  a  layer  of  mesogloea  for  which  Andres's  term  subcuticula 
may  be  employed.  The  distinction  between  the  cuticle  and 
this  layer  has  been  overlooked  by  most  authors.  It  was  rec- 
ognized by  Kolliker1,  however,  who  believed  it  to  be  a  portion 
of  the  cuticle.  Andres  recognized  its  true  nature,  considering 
it  simply  a  continuation  of  the  mesogloea. 

Below  the  subcuticula  is  the  ectoderm  (PI.  11,  fig.  6,  ec), 
which  forms  a  layer  0'08  mm.  in  thickness.  It  is  not  contin- 
uous, however,  but  is  divided  into  more  or  less  cubical  masses 
by  columns  of  mesogloea  extending  from  the  general  mass  of 
that  tissue  to  the  subcuticula.  A  peculiar  feature  of  the  ecto- 
derm of  this  species  is  the  presence  in  it  of  zooxanthellae.  In 
adult  actinians  these  structures  are  usually  confined  to  the  en- 
doderm,  but  I  have  observed  them  in  the  ectoderm  in  free- 
swimming  Iarva3,  in  which  layer  they  also  occur  according  to 
H.  V.  Wilson2  in  the  embryos  of  the  coral  Manicina.  It  is  pos- 
sible that  their  presence  in  the  ectoderm  of  M.  tuberculata  is  due 
to  the  thick  cuticle  and  subcuticula  preventing  a  rapid  aeration 
of  the  ectoderm  cells,  and  so,  by  favoring  the  accumulation  to 
a  certain  extent  of  carbon  dioxide,  producing  favorable  condi- 
tions for  the  growth  of  the  parasitic  algse.  The  ectoderm  thus 
buried  in  the  mesogloea  evidently  corresponds  with  what 
Kolliker,  in  the  admirable  account  he  has  given  of  the  ZOMII- 
than  mesogloea,3  terms  "eine  zusammenhangende  Schicht 
drusenartiger  Korper  "  and  which  he  believed  to  correspond  to 
the  ectoderm. 

The  endoderm  consists  of  low  cells  containing  numerous  zoo- 
xanthellse.  In  the  upper  part  of  the  column,  extending  from 

1  Kolliker.     Icones  Histologies.     Leipzig.     1865. 

2  H.  V.  Wilson.     On  the  Development  of  Manicina  areolata.     Journal  of  Mor- 
phology.    Vol.  II.     1888. 

3  A.  Kolliker,  loc.  cit. 


ZOOLOGY  OF  THE  BERMUDAS.  127 

the  margin  to  the  upper  row  of  tubercles,  is  a  single  strong 
sphincter  muscle  imbedded  in  the  mesogloea,  and  occupying 
nearly  its  whole  thickness. 

All  the  specimens  were  in  a  state  of  strong  contraction,  and 
I  was  not  able  to  see  the  tentacles.  Duchassaing  and  Michelotti 
state  that  they  are  small  tubercles.  My  sections  show  that 
they  are  arranged  in  two  cycles.  It  is  also  evident  that  they 
are  short,  but  they  can  scarcely  be  termed  tubercles.  Their 
mesogloea  is  thick,  especially  toward  the  base,  thinning  out 
somewhat  towards  the  apex.  Its  outer  surface  is  thrown  into 
rather  strong  muscular  processes. 

The  surface  of  the  stomatodaeum  is  thrown  into  numerous 
rather  high  folds,  the  ectoderm  being  elevated  on  slender  proc- 
esses of  the  mesogloea. 

The  mesenteries  are  arranged  on  the  microtypus  and  num- 
ber twenty-two  pairs.  Towards  their  base  the  mesogloea  is 
very  thick,  diminishing  gradually  towards  the  distal  edge. 
Just  at  the  base  there  is  a  sudden  diminution  of  the  thickiiet-s, 
so  that  they  are  attached  to  the  column  wall  by  a  thin  pedic-le. 
The  basal  portion  contains  the  usual  canal,  and  in  addition 
there  are  numerous  lacunae,  similar  to  those  of  the  column  wall 
in  every  respect.  M.  tuberculata  is  hermaphrodite,  and  I  am 
able  to  add  this  particular  to  the  definition  of  the  genus  given 
by  Erdmann.*  I  could  not  make  out  any  regularity  in  the 
arrangement  of  the  reproductive  elements  on  the  different 
mesenteries,  nor  did  there  seem  to  be  any  definiteness  in  their 
position  in  any  one  mesentery.  Sometimes  a  mesentery  would 
possess  ova  only,  but  usually  each  one  presented  both  ova  and 
spermatozoa. 

Corticifera  ocellata  (Ellis).        * 

Alcyonium  ocellatum.     Ellis  and  Solander,  1786. 
Palythoa  ocellata.     Lamouroux,  1821. 

A  number  of  small  colonies  of  a  Corticifera  were  obtained  at 
Shelly  Bay,  and  were  accompanied  by  a  label  referring  them 

*  A.  Erdmann,     loc.  cit. 


128  THE  BERMUDA  ISLANDS. 

to  the  above  species.  The  term  ocellata  was  first  given  by  Ellis 
and  Solander  to  a  form  which,  however,  was  very  poorly  char- 
acterized, so  much  so  that  certainty  of  identification  is  impos- 
sible. The  only  statement  in  the  description  of  which  use  may 
be  made  is  that  the  polyps  are  rust-colored.  Later  authors 
simply  copied  Ellis  and  Solander's  description,  until  Dana,*  evi- 
dently relying  on  the  figure  which  accompanies  the  earlier 
description,  adds  the  characteristic  that  the  polyps,  though  im- 
bedded in  coenenchyma  throughout  the  greatest  part  of  their 
extent,  are  yet  free  above.  Duchassaing  and  Michelotti  in 
their  paper  of  1860  described  a  form  under  this  name  which 
differs  somewhat  from  the  original  type  species,  and  is  proba- 
bly to  be  considered,  as  Andres  has  done,  a  distinct  form.  In 
their  later  paper  they  make  this  form  identical  with  a  form 
they  name  Palythoa  mammillosa,  a  name  taken  from  a  second 
imperfectly  characterized  form  mentioned  by  Ellis  and  Solander. 
In  fact,  so  much  confusion  is  introduced  by  Duchassaing  and 
Michelotti  as  to  render  it  very  difficult,  if  not  impossible,  to 
ascertain  what  forms  they  are  really  describing. 

Under  the  circumstances  I  have  thought  it  well  to  retain 
the  name  which  accompanied  the  specimens,  and  trust  that 
the  following  description  will  sufficiently  characterize  them  to 
allow  of  the  identification  in  the  future. 

The  polyps  are  grouped  together  in  small  masses,  and  pro- 
ject decidedly  above  the  surface  of  the  coenenchyma.  Their 
height  measured  from  the  lower  surface  of  the  coenenchyma  is 
1-2  cm.,  and  their  breadth,  measured  at  the  summit,  about  07 
cm.  in  the  fully  grown  individuals.  The  polyps  and  coenen- 
chyma are  densely  incrusted  with  particles  of  sand  and  other 
foreign  bodies,  anol  are  of  a  grayish  sandy  color,  sometimes 
deepening  to  a  rust  color. 

Upon  the  outside  of  the  column  is  a  rather  thick  cuticle, 
but  I  was  not  able  to  discover  whether  or  not  a  layer  of 
mesogloea  intervened  between  this  and  the  ectodermal  cells. 

*J.  D.Dana. — Zooph)tes.     United  States  Exploring  Expedition.     1840. 


ZOOLOGY  OF  THE  BERMUDAS.  129 

The  outer  portion  of  the  mesoglcea  for  about  half  its  thickness 
has  imbedded  in  it  foreign  bodies,  and  when  decalcified  is 
fenestrated  by  the  numerous  cavities  previously  occupied  by 
them.  The  internal  portion  of  the  layer  presents  the  structural 
features  found  in  other  Zoanthidse,  but  it  is  to  be  noticed  that 
foreign  bodies  occur  in  the  so-called  "  nutritive  canals  "  or 
lacunae.  The  sphincter  muscle  is  imbedded  in  the  mesogloea, 
is  single,  and  consists  of  a  single  row  of  cavities  containing 
muscle  fibres. 

The  tentacles  are  arranged  in  two  rows,  and  are  apparently 
fifty-six  in  number  in  the  specimens  examined.  Their  outer 
muscular  layer  is  weak,  and  the  mesogloea  is  homogeneous,  ex- 
cept upon  the  outer  face  of  the  tentacles,  where  it  contains  a 
number  of  granular  cells  similar  to  those  occurring  in  the 
column  mesoglcea  in  this  and  other  forms  already  described. 
Zooxanthellse  occur  in  the  ectoderm. 

The  ectoderm  of  the  disc  is  peculiar!  It  consists  of  high, 
much-vacuolated  cells  which  contain,  like  the  ectoderm  of  the 
tentacles,  zooxanthellse.  I  have  found  this  peculiar  structure 
of  the  disc  ectoderm  in  no  other  Zoanthids.  Unfortunately 
the  preservation  of  the  specimens  was  not  sufficiently  good  to 
allow  of  the  histological  details  being  studied.  The  gonidial 
groove  of  the  stomatodseum  is  rather  broad,  and  the  mesogloea 
lining  is  thickened  and  truncated  upon  the  endoderrnal  side, 
the  macrodirectives  being  inserted  into  each  angle  of  the 
truncation. 

The  mesenteries  are  arranged  on  the  microtypus,  there 
being  about  twenty-six  pairs.  The  basal  canal  is  large,  and 
contains  foreign  particles  similar  to  those  found  in  the  lacunae 
of  the  column.  The  mesoglcea  is  thickened  towards  the  base 
of  the  mesenteries  and  contains,  in  addition  to  the  basal  canal, 
several  others  nearly  circular  in  section  and  completely  filled 
with  spherical  granular  cells.  The  endoderm  throughout  con- 
tains zooxanthellse.  No  reproductive  organs  were  present. 

Cortioifera  glareola,  Les. 

Corticifera  glareola.     Lesueur.     1817. 
Palythoa  glareola.     Milne-Edwards.     1857. 


130  THE  BERMUDA  ISLANDS. 

The  identification  of  this  form  depends  mainly  on  the 
coloration,  which  Professor  Heilprin  informs  me  is  sufficiently 
similar  to  Lesueur's  description. 

The  polyps  form  encrusting  masses,'and  are  so  deeply  im- 
bedded in  the  coenenchyma,  that  in  contraction  a  slight  de- 
pression alone  indicates  the  position  of  the  various  individuals, 
or  in  some  cases  a  slight  annular  elevation.  The  species  is  by 
this  peculiarity  readily  distinguishable  from  C.  ocellata,  as 
well  as  from  C.flava  of  the  Bahamas,  which  stands  in  an  inter- 
mediate position  as  far  as  the  projection  of  the  polyps  above 
the  coenenchyma  is  concerned.  The  form  described  from  the 
Bermudas  by  Erdmann,  and  named  C.  lutea  by  Hertwig,  re- 
sembles C.  glareola  in  this  respect,  but  appears  to  differ  from  it 
in  other  points. 

The  mesogloea  is,  with  the  exception  of  a  narrow  band  im- 
mediately adjoining  the  endoderm  of  the  polyps,  richly  sup- 
plied with  imbedded  foreign  bodies,  so  that  the  entire  colony 
is  very  hard,  almost  stony  in  its  consistency.  C.  ocellata  is 
much  less  richly  provided  with  foreign  particles,  and  the  same 
is  the  case  with  Hertwig's  C.  lutea.  Whether  this  is  a  charac- 
teristic of  sufficient  importance  for  specific  distinction  can 
only  be  ascertained  by  the  examination  of  numerous  speci- 
mens of  some  species,  obtained  from  different  localities  and 
living  under  different  conditions.  In  fact,  our  knowledge  of 
the  histology  of  the  Zoanthidse  is  not  yet  sufficiently  advanced 
to  enable  us  to  ascertain  what  features  are  of  systematic  im- 
portance and  what  are  liable  to  extensive  individual  variation. 

The  sphincter  muscle  resembles  closely  that  of  Hertwig's 
C.  lutea.  It  is  imbedded  in  the  mesogloea  and  is  single,  con- 
sisting of  a  single  row  of  cavities  which  are  entirely  confined 
to  the  portion  of  the  column  which  is  invaginated  during  con- 
traction. All  the  cavities  contain  muscle  cells,  and  there  are 
none  of  the  empty  spaces  with  clearly  defined  walls  such  as  oc- 
cur in  C.  flava. 

The  mesenteries  are  arranged  on  the  microtypus,  and  in  the 
specimens  examined  there  were  about  eighteen  pairs  only. 


ZOOLOGY  OF  THE  BERMUDAS.  131 

The  mesogloea  is  delicate,  and  is  not  dilated  towards  the  base 
as  in  C.  ocellata,  and  in  consequence,  the  basal  canal  is  elon- 
gated. Notwithstanding  that  the  specimens  were  very  much 
macerated  it  was  possible  to  perceive  that  a  digestive  area, 
similar  to  that  described  as  occurring  in  Z.  flos-marinus,  was 
present,  just  below  the  stomatoda9um.  No  reproductive  organs 
were  present. 

The  stomatodaeum  presented  the  pyriform,  truncated  shape 
which  has  been  described  for  other  members  of  the  genus. 

It  seems  not  improbable  that  the  form  described  by  Hertwig 
as  C.  lutea  may  be  identical  with  this.  Alcoholic  specimens  of 
C.  glareola  show  no  trace  of  the  coloration  of  the  living  forms, 
but  are  of  a  universal  sandy  color.  In  the  very  slight  prom- 
inence of  the  polyps  above  the  coenenchyma,  in  the  structure 
of  the  sphincter  muscle,  and  in  the  slenderness  of  the  mesen- 
teries there  is  agreement  between  the  two,  and  these  are  points 
which  will  probably  prove  to  be  of  systematic  importance. 
On  the  other  hand,  there  is  dissimilarity  in  the  extent  of  the 
incrustation  by  foreign  bodies,  in  the  pigmentation  of  the 
endoderm,  which  is  wanting  in  C.  glareola,  and  apparently  in 
the  extent  of  the  development  of  the  longitudinal  muscles  of 
the  mesenteries,  which  cannot  be  said  to  be  well  developed  in 
C.  glareola.  This  last  character  is  probably  of  importance,  but 
the  first  two  are  probably  subject  to  variation  depending  upon 
the  conditions  of  life  and  the  food. 

The  evidence  then,  seems  to  be  in  favor  of  the  identity  of  the 
two  forms,  in  which  case  the  name  here  used  has  the  priority. 
It  seems  to  me  very  doubtful,  indeed,  if  Hertwig's  identifica- 
tion of  the  Bermuda  form  with  Quoy  and  Gaimard's  C.  lutea 
from  the  Feejee  islands  is  correct.  The  only  point  of  correspond- 
ence, judging  from  the  description  and  figures  given  by  Quoy 
and  Gaimard,*  is  the  slight  prominence  of  the  polyps  above  the 
coenenchyma  when  in  contraction. 

Gemmaria  Rusei,  Duch.  and  Mich.     (PI.  11,  figs.  7-9.) 

Gemmaria  Rusei.     Duchassaing  and  Michelotti.     1860. 

*  Quoy  and  Gaimard,  Zoologie  du  Voyage  de  la  Corvette  T  Astrolabe.  Paris.  1833. 


132  THE  BERMUDA  ISLANDS. 

I  was  pleased  to  find  in  the  Bermuda  collection  several 
specimens  of  a  form  which  evidently  belongs  to  the  same  genus 
as  the  form  from  the  Bahamas  which  I  described  as  Gemmaria 
isolata.  Several  anatomical  features  are  common  to  the  two. 
and  I  am  now  able  to  give  other  characteristics  which  may 
serve  to  distinguish  the  genus  more  definitely  than  was  done 
in  my  former  paper. 

The  polyps  of  G.  Rusei  (PL  11,  fig.  7)  are  solitary,  being 
attached  to  pebbles  without  the  development  of  any  coenen- 
chyma.  The  specimens  were  obtained  at  North  Rock,  and  are 
five  in  number.  The  upper  portion  of  the  column  is  larger 
than  the  lower,  so  that  the  polyps  have  the  shape  of  a  short 
stout  club;  the  lower  .portion  is  transversely  wrinkled  even  in 
the  expanded  condition,  as  is  noted  in  the  label  accompanying 
the  specimens.  The  height  of  the  column  is  about  2*5  cm.  in 
the  largest  specimens ;  the  diameter  of  the  upper  part  is  0*65 
cm.  and  of  the  lower  0*5  cm.  The  color  is  stated  on  the  label 
to  have  been  "  cinereous  throughout." 

The  column  wall  is  rather  thin,  and  is  occupied  throughout 
nearly  its  entire  thickness  by  foreign  bodies.  The  ectoderm  is 
covered  externally  by  a  cuticle,  but  I  was  unable  to  ascertain 
whether  a  layer  of  mesogloea  intervened  between  this  and  the 
surface  of  the  ectoderm.  The  structure  of  the  thin  layer  of 
mesogloea  unoccupied  by  foreign  bodies  is  as  in  other  Zoanthidse, 
and  calls  for  no  special  comment.  The  sphincter  is  single, 
and  imbedded  in  the  mesogloea ;  it  consists  for  the  most  part 
of  a  single  layer  of  cavities,  but  thickens  somewhat  towards  its 
upper  end.  All  the  cavities  contain  muscle  cells,  there  being 
none  of  the  empty  cavities  described  in  G.  isolata. 

The  tentacles  are  arranged  in  two  cycles,  and  have  only  a 
very  weak  ectodermal  musculature,  as  is  also  the  case  in  G.  iso- 
lata. Towards  the  base  and  upon  the  outer  surface  the  mesogloea 
contains  peculiar  granular  cells,  and  occasionally  enclosures 
of  foreign  bodies,  arid  this  likewise  occurs  in  G.  isolata. 

The  disc  is  traversed  by  a  number  of  ridges  which  radiate 
from  the  peristome  to  the  margin,  a  ridge  corresponding  to 


ZOOLOGY  OF  THE  BERMUDAS.  133 

each  tentacle  of  the  outer  cycle.  The  elevations  are  produced 
hy  thickenings  of  the  mesogloea  (PL  11,  fig.  9),  and  along  each 
ridge  the  ectodermal  muscle  cells  are  more  numerous  and 
larger  than  elsewhere.  G.  isolata  presents  similar  structures. 
Zooxanthelloe  occur  in  the  ectoderm  of  the  disc,  and  tentacles 
in  both  forms.  The  enclosures  in  the  mesogloea  of  the  disc, 
which  I  thought  might  possibly  be  muscle  cells  in  G.  isolata,  are 
seen  in  G.  Rusei  to  be  comparable  to  the  lacunae  of  the  column 
wall. 

The  mesogloea  of  the  stomatodreum  in  both  species  of  Gem- 
maria has  enclosures  of  granular  cells  (PL  11,  fig.  8),  as  a 
rule  one  such  enclosure  opposite  the  insertion  of  each  mesen- 
tery, especially  in  the  upper  part  of  the  stomatodaeum,  the  ar- 
rangement being  lost  in  the  lower  part.  The  gonidial  groove 
has  the  same  shape  as  that  of  G.  isolata. 

The  mesenteries  are  arranged  in  thirty-one  pairs  and  are  on 
the  microtypus.  The  mesogloea  thickens  towards  the  base  so 
that  the  basal  canal  is  almost  circular  and  not  elongated  as  in 
G.  isolata.  No  reproductive  organs  were  present. 

The  description  given  by  Duchassaing  and  Michelotti  of 
Gemmaria  Rusei,  with  which  I  identify  this  form,  is  very  im- 
perfect, but  so  far  as  it  goes  it  applies  to  the  Bermuda  species. 
The  form  described  by  Gray*  as  Triga  Philippinensis  is  very 
similar  in  external  form  and  is  in  all  probability  a  Gemmaria. 

Of  the  forms  described  above,  no  less  than  seven,  viz:  Con- 
dylactis  passiflora,  Phymanihus  cruci/er,  Zoanthus  flos-marinus, 
Mammillifera  turberculata,  Corticifera  ocellata,  C.  glareola  and 
Gemmaria  Rusei,  are  represented  in  the  West  Indian  fauna,  and 
of  the  other  three,  the  genera  Aiptasia  and  Phyllactis  also 
occur  in  the  islands  to  the  South,  leaving  only  the  genus 
Diplactis  as  a  characteristic  form  of  the  Bermudas.  No  doubt 
a  systematic  search  for  actinians  in  the  Bermudas  would  lead 
to  the  discovery  of  a  greater  number  of  West  Indian  forms, 
but  the  proportion  of  common  forms  given  above  is  sufficient 

*  J.  E.  Gray.     Notes  on  Zoantliinse  with  Descriptions  of  some  New  Genera.    Proc. 
Zool.  Soc.     London r     .1867. 


134  THE  BERMUDA  ISLANDS. 

to  show  that  the  actinian  fauna  of  the  Bermudas  has  been  de- 
rived from  that  of  the  West  Indies. 

EXPLANATION  OF  PLATES. 
bc.=basa,l  canal.  en.=endoderm. 

c.=column  wall.  /r.=fronds. 

cm.^circular  muscles.  ra.=margin. 

cu.— cuticle.  £>.— tentaculiform  fronds. 

d~ disc.  sp.=sphincter. 

di.=digestive  region  of  mesen- 

terial  filament.  sp1.— lower  sphincter. 

Eb.— Ectoderm.  £.=tentacle. 

PLATE  10. 

1.  Transverse   section   through   the   middle   region  of  the 
sphincter  of  Aiptasia  sp.  (?)     X  350. 

2.  Longitudinal  section  through  the  upper  half  of  the  column 
wall  of  Aiptasia  sp.  (?)     X  40. 

3.  Transverse  section  through  the  outer  edge  of  the  longitu- 
dinal mesenterial  muscles  of  a  specimen  of  Condyladis  passi- 
flora  from  the  Bermudas.     X  42. 

4.  Longitudinal  section  through  the  margin  and  adjacent 
parts  of  Dipladis  Bermudensis.     X  24. 

5.  Longitudinal  section  through  the  margin  and  adjacent 
parts  of  Oidactis  fasciculata.     X  21. 

6.  Transverse  section  through  the  longitudinal  mesenterial 
muscles    below   the   stomatodseum   in   Dipladis   Bermudensis. 
X  40. 

PLATE  11. 

1.  Perfect  mesentery  of  Dipladis  Bermudensis.     Natural  size. 

2.  Portion  of  transverse   section  of  sphincter   of  Dipladis 
Bermudensis.     X  100. 

3.  Transverse  section  of  mesenterial  filament  of  Zoanthus 
flos-marinus  just  below  the  stomatodeeum.     X  120. 

4.  Transverse  section  of  perfect  mesentery  of  Zoanthus  flos- 
marinus  slightly  below  the  stomatodseum.     X  50. 


ZOOLOGY  OF  THE  BERMUDAS.  135 

5.  Mammilli/era  tuberculata.     Natural  size. 

6.  One-fourth  of  a  portion  of  a  longitudinal  section  through 
the  column  wall  of  M.  tuberculata.     X  200. 

7.  Gemmaria  Rusei.     Natural  size. 

8.  Transverse  section  through  the  gonidial  groove  of  Gem- 
mar  ia  Rusei.     X  65. 

9.  Transverse   section   through   upper   part  of   column   of 
Gemmaria  Rusei.     X  24. 

HYDROID-CORALS. 

Apparently  both  of  the  common  West  India  species  of  mille- 
pore,  Millepora  alcicornis  and  M.  filiformis,  are  found  in  the  Ber- 
mudas ;  at  any  rate,  forms  answering  to  these  are  found  in  our 
collections.  I  feel  doubtful,  however,  if  the  two  should  not 
properly  be  classed  as  a  single  species,  seeing  how  great  is  the 
individual  variation,  and  how  closely  the  species  approximate 
one  another.  It  is  certainly  not  easy  to  separate  them  by  the 
characters  which  have  been  generally  indicated  by  systematists. 


VII. 


THE  ZOOLOGY  OF  THE  BERMUDAS  (continued). 


HOLOTHURIA. 

The  animals  of  this  order  are  in  places  exceedingly  abun- 
dant ;  indeed,  excepting  the  corals,  they  may  be  said  to  consti- 
tute the  most  distinctive  feature  of  the  fauna  of  the  sand  bot- 
toms. Where  other  forms  are  apparently  entirely  absent,  the 
black  masses  of  the  great  Stichopus  stand  out  in  prominent 
relief  over  the  white  bottom.  Motionless,  seemingly,  during 
the  greater  part  of  their  existence,  these  singular  creatures 
present  the  appearance  of  big  black  blotches  on  the  sand,  of 
which  they  consume,  whether  for  nourishment  or  otherwise, 
vast  quantities.  All  the  individuals  that  were  opened  had 
their  digestive  tracts  completely  filled  with  calcareous  par- 
ticles. 

The  following  are  the  species  of  holothurians  observed  by 
us,  only  one  of  which,  I  believe,  had  hitherto  been  noted  from 
the  Bermudas : 

Holothuria  Floridana,  Pourtales.    (Holothuria  atra,   Jager.)     PL  12,   figs.   6,   6a, 
7,  7a. 

I  identify  with  this  species  five  small  individuals  of  an 
olive-green  color  which  were  obtained  in  Castle  Harbor, 
and  which  in  a  general  way  agree  with  the  description  of  the 
species  given  by  Pourtales  (Proc.  American  Assoc.,  1851,  p.  12). 
Unfortunately,  no  figure  accompanies  the  description,  and  that 
part  which  pertains  to  the  calcareous  bodies  embodied  in  the 
skin  is  too  vague  to  permit  of  specific  determination.  Selenka 
(Zeitschrift  fur  wissenschqftliche  Zoologie,  xvii,  p.  324,  1867)  has 
supplemented  the  original  description  with  further  details  of 


ZOOLOGY  OF  THE  BERMUDAS.  137 

structure  and  with  illustrations  of  the  spicules,  which  prac- 
tically leave  no  doubt  in  my  mind  that  the  Bermudian  forms, 
even  though  differing  somewhat  from  the  type  described  by 
Pour-tales,  are  really  that  species.  I  have  examined  the  spicu- 
lar  bodies  of  all  the  individuals,  and  find  that  they  exhibit 
considerable  variation  (PI.  ,  figs.  6, 6a,  7,  7a).  This  is  especially 
noticeable  in  the  form  of  the  stools.  I  really  doubt  if  very 
much  dependence  can  be  placed  upon  these  bodies  as  furnish- 
ing characters  for  specific  distinction.  I  also  find  a  certain 
amount  of  variation  in  the  number  of  tentacles.  Thus,  while 
four  of  the  individuals  have  the  normal  number  of  tentacles, 
20,  one  has  only  10,  although  in  all  other  essentials  of  struct- 
ure it  agrees  with  the  remaining  four.  The  dorsal  surface  is 
distinctly  papillate.  The  elongated  yellowish  pedicels  of  the 
ventral  surface  are  irregularly  distributed,  as  stated  by  Selenka, 
and  I  could  not  determine  any  strictly  linear  disposition  such 
as  is  indicated  by  Pourtales. 

The  largest  specimen  measures  about  two  and  a  half  inches. 

Semper,  Ludwig,  and  Lampert  (Die  Seewalzen,  Semper's 
Reisen  im  Archipel  der  Philippines,,  1885,  p.  86)  identify  this 
species  with  the  Holothuria  atra  of  Jager  (1833),  whose  range  is 
made  to  be  practically  cosmopolitan — extending  from  the 
Radack  Archipelago  and  the  Sandwich  Islands  to  Adelaide, 
Zanzibar,  the  Red  Sea,  and  the  West  Indies — but  on  this  point 
I  can  offer  no  satisfactory  evidence,  never  having  had  an  op- 
portunity to  examine  authentic  specimens  of  Jager's  species. 

Holothuria  captiva,  Ludwig.     (PI.  12,  figs.  4,  4a.) 

Two  individuals,  agreeing  with  the  species  described  by 
Ludwig  from  the  Barbados. 

Holothuria  abbreviata,  n.  sp.    (PI.  12,  figs.  5,  8,  8a.) 

Among  the  smaller  forms  of  holothurians  is  one  which  in 
many  of  its  characters  agrees  most  closely  with  Lud wig's  H. 
captiva,  but  yet  differs  to  such  an  extent  as  to  compel  me  to  rec- 
ognize it  as  a  distinct  species.  Indeed,  by  many  systematists 
it  would  probably  be  made  the  type  of  a  distinct  sub-genus  or 


138  THE  BERMUDA  ISLANDS. 

genus.  The  distinguishing  peculiarity  is  the  abrupt  truncation 
of  the  body,  which  carries  the  vent  on  the  dorsal  surface,  im- 
mediately about  the  extremital  border.  In  the  single  specimen 
before  me  I  could  determine  only  17  tentacles,  with  as  many 
tentacular  vesicles,  and  but  a  single  Polian  body.  A  large 
Cuvierian  bundle  is  present.  The  pedicels  are' arranged  ven- 
trally  in  three  more  or  less  distinct  rows.  Color  olive  green. 
Length  about  two  inches. 

The  stools,  buttons,  and  fenestrated  plates  of  the  pedicels  are 
figured  on  plate  12.  It  will  be  seen  that  in  general  they  bear 
a  close  resemblance  to  those  of  Holothuria  captiva,  but  the 
rounded  summits  of  the  stools  serve  readily  to  distinguish 
them  from  the  somewhat  similar,  but  more  strictly  castellated, 
bodies  of  the  other  species. 

SEMPERIA. 
Semperia  Bermudensis,  n.  sp.     (PI.  12,  figs.  2,  2a,  3.) 

Body  cylindrical,  spindle-shaped,  tapering  almost  equally  to 
both  extremities.  Tentacles  10,  of  which  four  are  shorter  than 
the  remaining  6;  pedicels  crowded,  arranged  in  five  broad 
rows,  and  scattered  over  the  interambulacral  areas ;  two  genital 
bundles,  with  very  numerous  non-divided,  and  greatly  elon- 
gated filaments ;  two  Polian  vesicles ;  two  long  respiratory 
trees.  Color  grayish  white,  minutely  speckled  with  brown; 
five  narrow  longitudinal  brown  bands  separating  the  ambulac- 
ral  areas.  Length  about  3|  inches. 

Calcareous  bodies  consisting  of  baskets,  knotted  and  smooth 
buttons,  and  perforated  more  or  less  circular  disks ;  pedicels 
with  fenestrated  plates.  Calcareous  ring  with  long  back  proc- 
esses for  the  attachment  of  the  powerful  retractor  muscles. 

One  specimen,  from  the  north  shore  about  a  half-mile  west 
of  Flatts  Village. 

I  first  mistook  this  species  for  the  Semperia  (Colochirus)  gem- 
mata  of  Pourtales  (Proc.  Amer.  Assoc.  1851,  p.  11),  described 
from  Sullivan's  Island,  coast  of  South  Carolina,  but  the  more 
exact  descriptions  and  figures  of  that  species  given  by  Selenka 
and  Lam  pert  convince  me  that  it  is  quite  distinct.  Both 


ZOOLOGY  OF  THE  BERMUDAS.  139 

species  are  of  a  grayish-white  color,  but  no  mention  is  made  by 
either  of  the  authors  above  quoted  of  the  existence  in  the  Car- 
olinian form  of  the  five  longitudinal  brown  bands  which  extend 
over  the  entire  length  of  the  Bermudian  species.  Apart  from 
this,  Semper  ia  Bermudensis  differs  in  the  disposition  of  the  ten- 
tacles, the  greater  number  of  Polian  vesicles,  and  the  character 
of  the  spicular  buttons,  which  are  in  the  greater  number  of 
instances  strongly  knotted.  The  posterior  processes  of  the 
calcareous  ring  appear  also  to  be  much  more  elongated. 

From  Semperia  (Chtcumaria)  pundata,  described  by  Ludwig 
from  the  Barbados  (Arbeiten  aus  dem  zoolog.  zootom.  Institute  in 
Wurzburg,  ii,  1875,  p.  82)  the  species  differs,  apart  from  the  gen- 
eral scheme  of  coloring — tentacles  as  wrell  as  body — in  the 
different  disposition  of  the  tentacles  (9  equal  in  S.  pundata,  ac- 
cording to  Ludwig),  th6  smaller  number  of  Polian  vesicles  (5  in  S. 
pundata),  and  in  the  much  greater  number  of  filaments  com- 
posing the  genital  bundles.  The  vent  does  not  appear  to  have 
been  rayed. 

Ludwig  states  that  there  are  in  his  species  no  calcareous 
teeth  about  the  anal  aperture,  whereas  Lampert  just  as  posi- 
tively asserts  that  they  are  present  (Semper,  Philippinen,  1885, 
p.  152).  None  such  were  detected  in  the  Bermudian  form. 

STICHOPUS. 

Stichopus  diaboli,  n.  sp.     (PI.  13,  figs.  1,  la,  Ib,  2.) 

Body  stout,  more  or  less  quadrangular,  flattened  ventrally, 
and  bearing  two  rows  of  prominent  marginal  wart-like,  tuber- 
cles; sometimes  two  additional  rows  of  minor  tubercles  are 
noticeable  on  the  lateral  margins  of  the  dorsum.  Tentacles  20, 
unequal.  Dorsal  papilla  scattered,  not  prominent,  leaving  the 
surface  nearly  smooth.  Pedicels  and  papilke  on  ventral  sur- 
face arranged  in  three  broad  bands,  which  are  more  or  less  dis- 
tinct for  the  entire  length  of  the  body,  but  most  distinct  near 
the  extremities;  numerous  in  each  transverse  row. 

The  body-cavity  is  largely  occupied  by  the  greatly  developed, 
and  finely  dissected,  respiratory  apparatus,  and  by  the  loops  of 


140  THE  BERMUDA  ISLANDS. 

the  variously  branched  genital  organs,  which  are  disposed  in 
two  great  bundles.  Tentacular  vesicles  present.  Two  Polian 
vesicles.  Calcareous  ring  with  long  back  processes. 

Calcareous  bodies  in  the  form  of  stools  very  numerous  (PI. 
13,  fig.  16).  C-shaped  bodies  very  scanty,  and  possibly  in 
some  cases  entirely  wanting. 

Color  black,  somewhat  more  intensely  so  on  the  dorsal  sur- 
face, becoming  Vandyke  brown  or  chocolate  in  alcohol. 

Length,  about  one  foot;  width  of  corresponding  animal 
about  three  inches. 

Abundant  over  the  sandy  floor  of  the  entrance  to  Harring- 
ton Sound,  opposite  Flatts  Village,  in  Harrington  Sound,  and 
in  Castle  Harbor,  whence  it  was  obtained  in  several  of  our 
dredgings. 

I  have  little  doubt  that  this  species  is  the  dark-brown  form 
which  is  referred  to  by  Theel  as  having  been  obtained  by  the 
officers  of  the  Challenger  at  the  Bermudas,  and  which  is 
doubtfully  referred  by  that  authority  to  Semper's  Stichopus 
Haytiensis  (Report  on  the  Holothuroidea,  Challenger  Reports, 
Zoology,  XIV,  p.  162).  Only  a  single  specimen  appears  to  have 
been  obtained,  which  when  examined  was  too  deformed  to 
permit  of  positive  specific  determination.  I  cannot  agree 
with  The'eFs  determination.  Apart  from  the  differences  which 
Theel  himself  points  out,  is  the  great  difference  in  coloring. 
Semper  (Reisen,  Philippinen,  Holothurien,  1868,  p.  75)  states 
that  his  species  is  dark  chocolate-brown,  blotched  with  yellow 
spots,  which  form  five  longitudinal  bands,  corresponding  to 
the  interradii.  No  such  coloration  is  visible  in  our  species, 
although  probably  we  observed  as  many  as  a  hundred  in- 
dividuals, all  of  which  were  uniformly  black.  Semper's  de- 
scription of  the  coloring  of  Stichopus  Haytiensis  is  re-stated  by 
Lam  pert. 

Stichopus  xanthomela,  n.  sp.     (PI.  12,  fig.  1 ;  PI.  13,  fig.  3.) 

Body  stout,  flattened  ventrally,  and  bearing  on  the  basal 
margin  two  rows  (one  row  on  each  side,  as  in  the  preceding 


ZOOLOGY  OF  THE  BERMUDAS.  141 

species)  of  prominent  wart-like  processes.  Tentacles  18,  un- 
equal, whitish  or  gray,  edged  with  brown.  Dorsal  papillae 
fairly  prominent,  scattered.  Pedicels  on  ventral  surface 
crowded,  arranged  in  three  longitudinal  series,  five  to  eight,  or 
more,  in  each  transverse  row. 

Body-cavity,  as  in  the  preceding,  largely  occupied  by  the 
respiratory  tree  and  the  double  genital  bundle,  the  filamental 
processes  of  the  latter  much  finer  than  in  S.  diaboli.  Tentacu- 
lar vesicles  present.  One  (?)  Polian  vesicle. 

Calcareous  bodies,  in  the  form  of  stools  (PI.  13,  fig.  3),  very 
numerous  C-shaped  bodies  scarce,  in  the  form  of  broadly- 
opened  calipers.  Ground-color  reddish-yellow,  irregularly 
blotched  with  black  or  very  dark  brown.  The  spots  on  the 
ventral  surface  more  or  less  coalescent  in  the  median  line, 
forming  there  a  broad  longitudinal  band,  or  entirely  united  to 
form  a  uniformly  dark-colored  base;  on  the  back,  united  into 
two  irregularly  ramifying  or  wandering  bands. 

Length  of  longest  specimen  about  ten  inches ;  width  about 
two  and  a-half  or  three  inches. 

The  same  habitat  as  that  of  the  preceding  species,  although 
apparently  much  less  abundant. 

I  strongly  suspect  that  this  is  the  form  which  The"el,  in  his 
report  on  the  Challenger  holothurians  (loc.  tit,  p.  159),  identi- 
fies with  Stichopus  Mobil  (Semper),  one  specimen  of  which, 
"  rather  deformed  and  compressed  "  when  examined  by  Theel, 
was  obtained  at  the  Bermudas.  I  assume  the  identity  in  this 
case,  as  well  as  in  that  of  the  preceding  species,  on  the  ground 
that  the  two  species  here  described  are  the  characteristic  forms 
of  the  archipelago,  and  it  is  barely  possible  that  they  could 
have  escaped  the  attention  of  the  Challenger  people.  But  the 
identification  with  Semper's  species  appears  to  be  erro- 
neous. The  resemblance  to  Stichopus  Mobii  appears  to  rest 
talmos  wholly  upon  the  form  of  the  spicules,  which  are  largely 
similar  in  many  very  distinct  forms  of  Stichopus,  and  in  a 
general  scheme  of  coloring.  But  Semper  distinctly  states 
(Holothurien,  loc.  cit.,  p.  246)  that  the  characteristic  spots  are 


142  THE  BERMUDA  ISLANDS. 

almost  wholly  wanting  on  the  ventral  surface,  and  no  mention 
is  made  of  their  occurrence  there  by  Larnpert  in  his  revision 
of  the  species  of  the  genus  (op.  cit.,  p.  108).  Moreover,  Semper 
affirms  that  the  body  is  devoid  of  wart-like  tubercles,  whereas 
such  are  quite  prominent  in  the  Bermudian  form,  although 
not  as  prominent  as  in  Stichopus  diaboli.  Theel,  however, 
makes  no  mention  of  the  occurrence  of  tubercles  in  his  single 
specimen,  but  probably  through  contraction  in  alcohol  their 
existence  had  been  effaced.  The  number  of  pedicels  in  each 
transverse  row  seems  also  to  be  much  more  numerous  in  the 
Bermudian  species  than  in  Stichopus  Mobii. 

Another  apparently  related  form  is  Stichopus  errans  of 
Ludwig  (Arbeiten  zoolog.  zootom.  Inst.,  Wurzburg,  1875,  p.  97), 
described  from  a  specimen  in  the  Hamburg  Museum,  reputed 
to  have  come  from  the  Barbados.  But  in  this  species  there 
appear  likewise  to  be  no  lateral  tubercles,  nor  is  the  coloring 
like  that  of  our  species,  although  in  this  regard  there  may  be 
considerable  variation.  The  number  of  tentacles  is  stated  by 
Ludwig  to  be  19,  and  their  color  yellow.  The  form  from  the 
Barbados  which  is  somewhat  doubtfully  referred  by  Th£el  (loc. 
cit.,  p.  191)  to  Ludwig's  S.  errans  would  seem  to  be  more  nearly 
related  to  the  Bermudian  species. 

ASTEROIDEA. 

We  obtained  but  a  single  species  of  star-fish  on  the  Ber- 
mudian coast.  This  is  the  Asterias  Atlantica  of  Verrill,  a  form 
which  had  already  been  previously  noted  from  the  Bermudas 
(Trans.  Conn.  Acad.  Sciences,  i,  p.  368),  and  whose  range 
extends  to  the  Abrolhos  Reef,  Brazil.  With  very  few  excep- 
tions the  rays  were  either  six  or  eight  in  number,  and  of  the 
total  number  of  individuals  examined  I  believe  that  not  over 
two  had  five  arms.  The  species  exhibits  a  marked  want  of 
constancy  in  ornamentation  and  coloring,  the  dorsal  spines 
being  in  some  cases  acute,  while  in  others  they  are  terminated 
by  a  minute  bead ;  again,  while  the  maculation  is  brown  in 


ZOOLOGY  OF  THE  BERMUDAS.  143 

some  individuals,  in  others  it  is  blue,  or  of  both  colors  combined. 

Asterias  Atlantica,  Verrill. 

Common  in  the  entrance  to  Harrington  Sound,  opposite 
Flatts  Village — under  stones;  dredged  in  Harrington  Sound. 

Linckia  Guildingii,  Gray. 

A  single  specimen,  marked  as  having  been  collected  by  Mr. 
Jarmey  in*  the  Bermudas,  is  in  the  possession  of  the  Academy 
of  Natural  Sciences. 

OPHIUROIDEA. 

Six  species  of  ophiurians  were  obtained  in  our  dredgings 
and  under  rock  shelters,  the  greater  number  of  which,  so  far  as 
I  am  aware,  had  not  hitherto  been  reported  from  the  Bermudas. 
For  a  critical  examination  and  review  of  the  species  I  am  in- 
debted mainly  to  my  assistant,  Mr.  J.  E.  Ives,  who  has  made  a 
careful  study  of  all  the  species  in  the  collections  of  the  Academy 
of  Natural  Sciences.  From  an  examination  of  many  of  these 
forms  I  feel  satisfied  that  too  much  dependence  should  not  be 
placed  upon  the  constancy  in  minute  details  of  either  the  form 
or  relative  size  of  the  arm  plates  and  their  appendages,  nor 
upon  an  exact  scheme  of  coloration.  These  characters,  and 
others  that  may  be  added,  which  have  been  drawn  in  very 
close  limits  by  Mr.  Lyman  in  his  several  memoirs,  vary  ma- 
terially within  the  limits  of  the  same  individual,  and  render  the 
discrimination  of  species  which  have  been  most  "elaborately  " 
defined  as  to  exact  lengths  and  breadths  of  the  arm-shields  and 
oval  plates,  the  precise  form  and  number  of  the  arm-spines, 
etc.,  a  matter  of  almost  hopeless  impossibility. 

Ophiocoma  crassispina,  Say. 

One  specimen,  taken  at  low  water  from  the  North  Rock, 
which  agrees  perfectly  with  the  species  described  by  Say  from 
the  coast  of  Florida  (Jourri.  Acad.  Nat.  Sci.,  Phila.  v,  p.  147). 
This  species  is  generally  considered  to  be  identical  with  the 
Ophiocoma  (Ophiura)  echinata  of  Lamarck,  but  I  am  disposed 
to  consider  this  identification  erroneous,  unless,  indeed,  several 


144  THE  BERMUDA  ISLANDS. 

distinct  forms,  as  has  been  averred  by  Miiller  and  Troscbel 
(System  der  Asteriden,  1842,  p.  98),  were  included  by  Lamarck 
in  bis  species.  Two  distinct -forms,  closely  related  to  eacb 
other,  certainly  do  occur  in  the  West  Indies,  one  of  which,  with 
more  blunt  arm  spines,  is  clearly  Say's  species,  while  the  other, 
with  more  elongated  arm  spines,  and  much  less  stoutly  devel- 
oped uppermost  spine,  more  nearly  corresponds  to  the  general 
type  of  Lamarck's  species. 

Ophiocoma  pumila,  Liitken. 

A  fragmentary  specimen;  exact  locality  unknown.  This 
species  had  been  recorded  by  the  Challenger  from  Bermuda. 

Ophiostigma  isacantha,  Say. 

Two  very  young  specimens,  dredged  in  Harrington  Sound. 

Ophiactis  Mulleri,  LUtken. 

0.  Krebsii,  Lutkenf 

Two  very  young  specimens,  dredged  on  the  north  shore  be- 
tween Bailey's  Bay  and  Shelly  Bay. 

Ophionereis  reticulata,  LUtken. 

Very  abundant  at  low  tide  in  the  rock  shelters  of  Shelly  Bay ; 
also  under  stones  at  the  entrance  to  Harrington  Sound. 

Ophiomyxa  flaccida,  LUtken. 

One  specimen,  dredged  in  Bailey's  Bay. 
ECHINOIDEA. 

The  number  of  species  of  echinoids  observed  by  us  is  six,  of 
which  five  had  already  previously  been  ascribed  to  the  archi- 
pelago ;  Oidaris  tribuloides,  so  far  as  I  am  aware,  had  not 
hitherto  been  collected — at  any  rate,  I  have  been  unable  to 
find  any  mention  of  its  occurrence  there.  One  species,  Mellita 
sexforis,  we  did  not  ourselves  collect,  the  specimens  in  our  pos- 
session having  been  kindly  donated  to  us  by  local  collectors. 

Cidaris  tribuloides,  Bl. 

Fairly  abundant  among  the  coral  shelters  of  the  North 
Rock. 

Diadema  setosa,  Gray. 


1 


ZOOLOGY  OF  THE  BERMUDAS.  145 

This  species,  one  of  the  gems  among  sea-urchins,  is  exceed- 
ingly abundant  in  the  flats  about  the  North  Rock.  All  the 
individuals  occupied  recesses  in  the  coral  growth,  which  they 
had  by  some  means  probably  managed  to  keep  open.  It  seems 
hardly  likely  that  they  should  have  crept  into  these  shelters 
after  they  had  been  already  formed,  and  that  the  association 
is  one  of  mere  selection. 

The  species  is  also  abundant  in  the  moderately  deep  water 
that  lies  within  the  reef  border. 

Hipponoe  esculenta,  Leske. 

North  Rock,  and  the  deeper  water  within  the  growing  reef. 

Echinometra  subangularis,  Leske. 

Several  specimens  from  the  flats  about  the  North  Rock. 
There  is  a  certain  amount  of  variation  in  the  coloration  of  the 
spines  which  ranges  from  olive  or  sea-green  to  purple. 

Toxopneustes  variegatus,  Lamk. 

We  found  this  species  very  abundant  in  Harrington 
Sound,  where  it  rarely  escaped  being  hauled  up  in  our  dredge. 
It  seems  to  frequent  the  calcareous  bottom  to  a  depth  of  10-12 
fathoms,  or  even  more.  Probably  the  species  is  equally  abun- 
dant elsewhere. 

Mellita  sexforis,  Agassiz. 

As  before  remarked,  we  did  not  ourselves  obtain  any  speci- 
mens of  this  species.  It  is  said  to  be  abundant  along  the  cal- 
careous bottoms  of  some  of  the  inlets,  as,  for  example,  opposite 
Flatts  Village. 


VIII. 


ZOOLOGY  OF  THE  BERMUDAS  (continued). 


CRUSTACEA. 

For  the  following  notes  on  the  Crustacea  I  am  principally 
indebted  to  Mr.  Witmer  Stone,  one  of  my  assistants  on  the 
trip,  who  has  made  a  careful  study  of  all  the  specimens,  as  well 
as  of  the  allied  and  identical  species  contained  in  the  collections 
of  the  Academy  of  Natural  Sciences.  In  the  case  of  in  any 
way  doubtful  forms  I  have  personally  satisfied  myself  as  to 
the  determinations,  particularly  in  cases  where  the  geo- 
graphical range  appeared  to  indicate  possible  or  probable 
error.  The  occurrence  in  the  Bermudas  of  a  number  of  what 
had  hitherto  been  considered  to  be  distinctively  Pacific  or  Old 
World  types,  as  for  example,  Palemonella  tcnuipes  (Sooloo  Sea), 
Palemon  affinis  (Pacific),  Penssus  velutinus  (Pacific) — may  be 
considered  positive,  even  though  it  be  opposed  to  the  common 
facts  of  zoogeography.  But  this  anomaly  in  distribution  is 
again  repeated  among  the  Mollusca,  as  will  be  seen  in  the 
enumeration  of  species  further  on. 

The  total  number  of  species  here  enumerated  is  not  very 
large,  but  yet  it  is  considerably  in  excess  of  the  number 
published  in  any  previous  paper,  probably  one-half  of  the 
species  being  now  for  the  first  time  credited  to  the  Bermudas. 
The  species  of  some  of  the  remaining  groups — the  Isopoda, 
Amphipoda — still  await  analysis  and  determination. 

BRACHYURA. 

Microphrys  bicornutus,  Latr. 


ZOOLOGY.    ARTHROPODA.  14? 

Three  females  and  one  male,  collected  on  the  beach  at  the 
entrance  to  Harrington  Sound. 

Mithraculus  hirsutipes,  Kingsley. 

Two  males  and  one  small  female,  which  agree  in  every  way 
with  the  description  of  the  species  given  by  Kingsley  (Proc. 
Bost.  Soc.  Nat.  Hist.,  20,  p.  147),  except  in  the  number  of  teeth 
on  the  fingers,  a  character  which  appears  to  be  very  variable. 
The  three  individuals  differ  in  this  respect  among  themselves. 

Actaea  setigera,  Milne-Edwards. 

One  male  dredged  off  Shelly  Bay.  The  individual  differs 
from  the  description  given  by  Milne-Edwards  (Now.  Arch,  du 
Miis.  d'  Hist.  Nat.  i,  p.  271,  pi.  xviii,  fig.  2)  in  having  the  color 
of  the  outside  of  the  hands  red,  instead  of  black.  It  however 
agrees  precisely  with  specimens  attributed  to  Milne-Edwards' 
species  in  the  collections  of  the  Academy,  and  labeled  as  com- 
ing from  the  Florida  reefs.  The  species  has  also  been  recorded 
from  Cuba 

Panopaeus  Herbstii,  var.  serrata,  De  Saussen. 

Numerous  small  specimens,  both  male  and  female,  from  un- 
der stones  on  the  beach  of  St.  George's  Causeway,  and  at  the 
mouth  of  Harrington  Sound.  The  specimens  vary  greatly  in 
color,  some  being  very  light,  others  dark  brown,  while  a  few  are 
reddish  ;  otherwise  they  are  identical  in  structure. 

The  species,  described  in  the  Hist.  Nat.  du  Mexique  et  dcs 
Antilles  (Crustac.,  p.  16,  pi.  1,  fig.  7),  had  previously  been  recorded 
from  the  Bermudas. 

Lobopilumnis  Agassizii,  Stirapson. 

One  small  male,  agreeing  well  with  Stimpson's  description 
(Bull.  Mus.  Comp.  Zool.,  ii,  p.  142)  except  in  that  it  lacks  the 
subhepatic  spine.  Recorded  from  Bermuda  and  Florida. 

Neptunus  hastatus.  L. 

N.  dicanthus. 
Two  small  males. 

Geocarcinus  lateralis,  Frem. 


148  THE  BERMUDA  ISLANDS. 

Numerous  large  specimens,  from  the  banks  and  fields  near 
the  south  shore.  We  found  them  specially  abundant  near  the 
locality  known  as  Spanish  Mark  or  the  Chequer  Board,  and 
again  not  far  from  Peniston  Pond.  The  burrows  in  places  ex- 
tend diagonally  three  or  four  feet,  or  even  more,  beneath  the 
surface,  and  the  animals,  rapidly  retreating  into  these,  are  fre- 
quently difficult  to  capture. 

This  is,  doubtless,  the  species  that  is  referred  to  by  Willemoes- 
Suhin  in  the  Challenger  narrative  as  Gecarcinus  latcralis,  and 
is  apparently  the  G.  lagostoma  (?)  described  by  Miers  in  the 
systematic  portion  of  the  Challenger  Reports  (Zoology,  XVII? 
p.  218),  in  so  far  as  this  description  applies  to  the  single  Ber- 
muda specimen. 

Nautilograpsus  minutus,  L. 

One  small  specimen  dredged  off  Shelly  Bay. 

Grapsus  maculatus,  Catesby. 

One  large  female,  and  numerous  empty  shells  from  Harris's 
Bay,  south  shore. 

Pachygrapsus  transversus,  Gibbcs. 

Numerous  specimens,  including  ovigerous  females;  very 
abundant  on  the  rocks  about  the  mouth  of  Harrington  Sound, 
and  also  on  the  Pigeon  Rocks,  Bailey's  Bay. 

Recorded  from  Florida,  West  Indies,  Australia. 

Cyclograpsus  integer,  Milne-Edwards. 

One  small  female.  Species  recorded  from  Brazil  and  Florida. 

Goniopsis  cruentatus,  Latr. 

One  female,  from  the  mangrove  swamp  of  Hungary  Bay, 
south  shore.  Although  the  species  was  very  abundant  at  this 
locality  we  only  succeeded  in  catching  a  single  individual. 
The  mangrove  crab,  or  "  mangrove  climber,"  as  the  animal  is 
sometimes  called,  burrows  among  the  thickets  of  mangrove 
stems  and  roots,  up  which  it  not  infrequently  climbs  to  a  height 
of  several  feet.  The  great  similarity  existing  between  its  color- 
ing and  that  of  the  bright  and  partially  withered  leaves  of  the 


ZOOLOGY.     ARTHROPODA.  149 

mangrove,  especially  in  the  shades  of  yellow  and  red,  renders 
the  animal  difficult  of  detection,  and  often  at  a  distance  of  only 
a  few  feet,  buried  among  the  fallen  leaves,  these  agile  creatures 
escaped  observation,  even  when  attentively  sought  after.  We 
have  here  one  of  the  most  remarkable  instances  of  protective 
coloring,  or  semi-mimicry,  with  which  I  am  acquainted. 

Sesarme  cinerea.  Bosc. 

Numerous  specimens,  from  the  beach  of  Flatts  Village. 
The  species  was  seen  almost  everywhere  scampering  over  the 
rocks. 

Calappa  fiammea,  Herbst. 

A  single  male  individual  obtained  through  purchase.  Spe- 
cies previously  recorded  from  the  Bermudas. 

ANOMURA. 

Petrolisthes  armata,  Gibbes. 

Five  specimens,  obtained  on  the  beach  of  Flatts  Village, 
which  appear  to  be  identical  with  the  form  described  under 
this  name  from  Florida  (Proc.  Amer.  Assoc.,  1850,  p.  190). 

Cenobita Diogenes,  Latr. 

A  number  of  living  specimens  obtained  at  Wistowe,  opposite 
Flatts  Village,  and  kindly  presented  to  us  by  Miss  Edith 
Allen,  daughter  of  the  American  Consul.  Most  of  the  animals 
are  still  living  (July),  and  apparently  flourishing,  twelve 
months  after  their  capture.  The  shells  occupied  by  the 
largest' individuals  are  those  of  Natica  catcnoides. 

Calcinus  obscurus,  Stimpson. 

Several  specimens  obtained  on  the  beach  of  Flatts  Village. 

Clibenarius  (Pagurus)  tricolor,  Gibbes. 

Numerous  on  the  beach  of  Flatts  Village  and  at  the  St. 
George's  Causeway ;  under  stones,  etc. 

MACRURA. 

Palinurus  Americanus,  Lamk, 


150  THE  BERMUDA  ISLANDS. 

We  observed  a  number  of  specimens  of  the  large  Bermuda 
crayfish,  but  unfortunately  obtained  none.  I  am  unable, 
therefore,  to  state  positively  if  the  species  is  correctly  referred, 
but  in  all  probability  it  is  the  same  as  the  common  West 
Indian  form. 

Scyllarus  sculptus,  Milne-Edwards. 

One  specimen,  purchased  at  the  Crawl,  which  agrees  with 
Milne-Edwards'  description  (Hist.  Nat.  des  Crust.,  ii,  p.  283)  and 
Lamarck's  illustration  in  the  Encydoptdie,  pi.  320.  The 
locality  of  the  original  specimen  appears  to  have  been  un- 
known, nor  have  I  been  able  to  obtain  data  regarding  this 
species  from  any  of  the  later  writers,  by  many  of  whom  it  is 
entirely  ignored. 

Alpheus  avarus,  Fabr. 

A.  Edwardsii,  Audouin. 

A.  Bermudensis,  Spence  Bate. 

A  series  of  some  twenty  specimens  collected  at  the  same 
locality  shows  considerable  variety  of  form.  The  smaller 
specimens  are  evidently  the  A.  Bermudensis  of  the  Challenger 
Reports,  while  the  larger  ones,  agreeing  with  these  in  the 
structure  of  the  head,  etc.,  more  nearly  approximate'  in  the 
configuration  of  the  hand  A.  avarus  and  A.  Edwardsii,  the 
former  a  common  Old  World  species,  and  the  latter,  a  species 
described  from  the  Cape  Verde  Islands.  Our  series  contains 
what  might  be  considered  undoubted  representatives  of  all 
three  (so-called)  species,  showing  all  the  gradations  that  unite, 
or  separate  the  forms  from  one  another.  Hence,  I  am  con- 
strained to  look  upon  them  as  mere  varietal  forms  of  a  single 
species,  the  Alpheus  avarus  of  Fabricius.  The  older  the  speci- 
mens, the  more  deeply  grooved  is  in  most  cases  the  hand. 

Alpheus  minus,  Say. 

A  number  of  species  taken  from  sponges  and  tunicates 
collected  in  Harrington  Sound.  All  the  individuals  were  of 
small  size,  measuring  rather  less  than  an  inch  in  length, 
although  the  females  were  abundantly  provided  with  eggs. 

Alpheus  formosus,  Gibbes, 


ZOOLOGY.     ARTHROPODA.  151 

One  specimen  (dredged)  which  agrees  well  with  Gibbes'  de- 
scription (Proc.  Amer.  Assoc.,  1850,  p.  196),  and  seems  to  indi- 
cate that  the  species  is  distinct  from  Alplieus  minus,  with  which 
it  is  united  by  Kingsley.  The  specimen  is  larger  than  any  of 
the  individuals  of  A.  minus,  and  is  also  differently  colored, 
although  appearing  identical  in  alcohol. 

Palaemonella  tenuipes,  Dana. 

Several  specimens  dredged  off  Shelly  Bay,  which  agree  per- 
fectly with  the  species  described  by  Dana  from  the  Sooloo  Sea 
(U.  S.  Exploring  Expedition,  Crustacea,  p.  582).  The  remark- 
able distribution  here  indicated  induced  me  to  make  a  very 
careful  examination  of  the  Bermudian  species,  which  has  left 
no  doubt  in  my  mind  as  to  the  identity  of  the  forms  from  the 
antipodal  regions  of  the  earth's  surface.  The  only  other 
known  species  of  Palaamonella,  P.  orientalis  (Dana),  is  likewise 
an  inhabitant  of  the  Sooloo  Sea  (Dana,  op.  cit. ;  Spence  Bate, 
Challenger  Reports,  Zoology,  XXIV,  p.  786). 

Palsemon  affinis,  Milne-Edwards. 

Numerous  specimens  from  shallow  water,  Castle  Harbor. 
All  are  exactly  like  one  another  except  in  the  number  of  teeth 
on  the  beak,  which  may  be  8  above  and  4  below,  or  in  rela- 
tions of  8-3,  7-3,  9-3,  and  9-4.  This  character  is  manifestly 
a  very  variable  one,  and,  therefore,  of  little  or  no  value  from 
a  classificatory  point  of  view.  The  specimens  agree  well  with 
the  descriptions  and  figures  of  A.  affinis,  although  that 
species  has  hitherto  been  recorded,  as  far  as  I  am  aware,  only 
from  the  Pacific  (obtained  by  Dana  off  New  Zealand).  The 
species  is  near  to  the  Eurafrican  P.  squilla,  but  yet  sufficiently 
distinct  to  permit  of  ready  recognition  as  only  an  allied  form. 

It  is  remarkable,  in  view  of  the  distribution  and  the  num- 
ber of  specimens  that  we  obtained  of  this  species,  and  the 
position  of  the  island  group,  that  we  should  have  failed  to  ob- 
tain any  individuals  of  the  common  form  of  the  eastern 
United  States,  Palxmon  vulgaris.  Whether  the  species  is 


152  THE  BERMUDA  ISLANDS. 

entirely  absent  or  not  I  cannot  of  course  say,  but  it  is  surpris- 
ing that  it  should  not  have  been  observed  by  us. 

Penaeus  velutinus,  Dana. 

One  specimen,  which  agrees  with  the  figure  and  description 
of  the  species  obtained  by  Dana  off  the  Sandwich  Islands  (U. 
S.  Exploring  Expedition,  Crustacea,  p.  604),  and  which  was 
subsequently  collected  by  the  Challenger  party  at  various 
points  in  the  Pacific,  and  between  Australia  and  New  Guinea 
(Challenger  Reports,  Zoology,  XXIV,  p.  253).  This  species,  as 
well  as  all  the  immediately  related  forms,  has,  as  far  as  I 
know,  been  found  thus  far  only  in  the  Pacific.  The  case  is, 
therefore,  another  example  of  remarkable  geographical  distri- 
bution. 

STOMATOPODA. 

Gonodactylus  chiragra,  Latr. 

One  specimen  from  the  beach  of  Flatts  Village. 

OBSERVATIONS  ON  THE  INSECTS  OF  THE  BERMUDAS, 

BY 
P.  R.  UHLER. 

The  present  list  of  insects  enumerates  chiefly  those  brought 
together  by  the  recent  exploration  of  Prof.  Heilprin,  and  it 
does  not  include  the  specimens  belonging  to  the  orders 
Coleoptera,  Lepidoptera,  and  Hymenoptera.  Although  con- 
stituting only  a  small  collection,  it  is  of  much  interest  as 
throwing  new  light  upon  a  recently  constituted  fauna  which 
has  been  only  superficially  noticed.  But  very  few  insects  have 
hitherto  been  recorded  from  this  group  of  coral  islands,  and 
much  arduous  collecting  is  still  needed  to  gather  a  full  series 
of  the  insects  settled  there.  Representatives  of  large  groups  in 
nearly  all  the  orders  have  not  yet  been  reported  as  occurring 
on  these  islands,  although  we  know  that  the  conditions  are 
favorable  for  the  settlement  and  increase  of  many  of  them. 
As  a  notable  instance  we  may  cite  the  absence  of  such  families 


ZOOLOGY.    ARTHROPODA.  153 

as  Hydrobatidac,  Notoncctidae  and  Corisidae,  in  the  aquatic 
Hemiptera;  and  of  the  Ephemeridae  among  the  Pseudoneuroptera. 
White  ants  and  Psocidae  likewise  remain  unrecorded  ;  and  the 
Diptera,  a  numerous  host,  seem  to  have  been  almost  totally 
ignored.  That  part  of  the  assemblage  to  which  attention  has 
been  hitherto  directed  is  almost  entirely  Nearctic  in  character, 
and  corresponds  with  the  fauna  which  exists  in  the  eastern 
part  of  the  United  States  from  Cape  Cod  to  northern  Florida. 
A  very  few  species,  such  as  Blabem  Americana  and  Labidura 
riparia,  occur  in  the  Bermudas,  but  they  are  wanderers  which 
frequent  vessels,  and  are  liable  to  be  transported  to  places 
where  they  make  no  permanent  stay.  There  are,  however, 
multitudes  of  Neotropical  forms,  residents  of  the  West  Indies 
and  southern  Florida,  which  we  look  for  in  connection  with 
the  palmettos  and  tropical  fruit  trees  and  shrubs  that  are  now 
permanently  settled  in  those  islands;  but  these  forms  are  still 
lacking  in  our  collections.  Can  it  be  that  these  insect  absentees 
are  only  such  as  live  in  the  upper  parts  of  the  high  trees,  and 
that  do  not  descend  during  the  daylight  so  as  to  be  noticed  by 
collectors?  Mr.  J.  M.  Jones,  in  his  "  Naturalist  in  Bermuda," 
has  given  some  account  of  a  few  insects  belonging  to  this  lo- 
cality, but  his  attention  seems  to  have  been  directed  almost 
exclusively  to  the  showy  or  more  conspicuous  kinds.  It  is 
therefore  with  earnest  solicitude  that  we  await  the  time  when 
some  acute  collector  will  undertake  to  solve  the  problem  of 
insect  settlement  which  lies  deeply  buried  in  the  history  of 
this  little  group  of  islands. 

HEMIPTERA. 

CYDNID^J. 

Pangaeus  bilineatus,  Say. 

A  fore-leg  only  of  this  curious  black  burrowing  Cydnid  was 
present  in  the  bottle  of  specimens.  It  agrees  with  the  same  or- 
gan of  some  individuals  in  my  own  collection ;  and  I  had 
previously  examined  a  perfect  specimen  of  this  species  which 
was  brought  from  Bermuda  by  Mr.  J.  M.  Jones. 


154  THE  BERMUDA  ISLANDS. 

PENTATOMIDJE. 

Nezara  viridula,  Linn. 

One  specimen,  a  female  of  the  uniformly  green  variety,  is 
present  in  the  collection.  This  species  has  been  widely  dis- 
tributed throughout  most  parts  of  the  warm  divisions  of  both 
the  Old  and  the  New  World.  It  is  common  in  North  Carolina, 
Georgia  and  Florida,  besides  the  West  Indies,  and  it  might 
readily  have  been  transported  to  Bermuda  with  plants  by  ves- 
sels from  either  of  the  localities  mentioned. 

JASSIDJE. 
Coelidia  olitoria,  Say. 

Only  the  head  of  a  specimen  occurs  with  the  other  insects 
in  the  bottle.  This  insect  is  easily  identifiable,  but  it  must  be 
regretted  that  the  entire  insect  was  not  present,  for  further  in- 
vestigation. This  little  leaf-hopper  is  very  common  upon  the 
black  alder  in  many  of  the  Atlantic  States,  and  it  is  a  matter 
of  much  interest  to  know  upon  what  plant  it  lives  in  Bermuda. 

HOMOPTERA. 
CICADIDJE. 

Cicada  tibicen,  Linn.=C.  pruinora,  Say. 

Said  to  occur  on  the  main  island.  Mr.  J.  M.  Jones  says :  "  A 
very  noisy  individual,  very  appropriately  named  'scissor 
grinder',  may  certainly  be  heard,  if  not  seen,  during  the  hot 
weather.  It  is  a  very  quick  sighted  insect,  and  is  difficult  to 
capture.  It  remains  perfectly  motionless  until  the  net  is 
drawn  towards  it,  when  off  it  starts  with  a  swift  jerk  and  a 
loud  buzz  of  derision."  This  is  our  common  green  Cicada  of 
the  United  States,  and  it  does  not  belong  to  Fidicina  as  the 
author  quoted  supposes. 

PSEUDONEUROPTERA. 

Mesothemis  longipennis,  Burm. 

A  damaged  specimen  is  present.  It  proves  to  be  a  male  of 
the  strongly  colored  variety,  with  the  base  of  the  wings, 


ZOOLOGY.     ARTHROPODA.  155 

especially  of  the  posterior  ones,  deeply  suffused  with  fulvous. 

Lestes  unguiculata   Hagen. 

By  putting  together  the  pieces  of  a  disintegrated  specimen, 
it  has  been  possible  to  identify  this  very  interesting  little 
species.  It  proves  to  be  a  female,  of  the  fully  developed  type 
of  coloration,  and  differs  in  no  respect  from  the  well  matured 
adults  which  are  common  in  New  Jersey  and  Maryland. 

The  foregoing  are  both  freshwater  types  of  the  order,  and 
must  have  passed  through  their  young  stages  in  places  where 
suitable  food  could  be  procured.  This  goes  to  show  that  ponds 
or  swamps  of  fresh  or  mildly  brackish  water  must  exist  in  the 
vicinity  of  the  places  from  which  these  specimens  were  taken. 
Neither  of  them  belongs  to  the  strong-winged  and  widely  rov- 
ing Odonata,  which  fly  without  hesitation  across  hundreds  of 
miles  of  open  ocean.  Possibly  the  progenitors  of  these  species 
might  have  been  wafted  by  high  winds  across  the  six  hun- 
dred miles  of  oceanic  surface  between  the  coast  of  Carolina 
'and  the  Bermuda  Islands.  We  know  that  strong  winds,  blow- 
ing off  the  mainland  of  Maryland  and  Virginia,  carry  count- 
less numbers  of  nearly  all  kinds  of  insects  out  over  the  ocean, 
and  that  many  of  these  being  dropped  into  the  waves  are  re- 
turned to  the  shores  by  the  tides  and  piled  up  in  windrows 
along  the  beaches.  Among  these  we  have  often  found  the 
half  drowned  dragon-flies  mixed  in  with  the  thick  piles  of 
beetles,  bugs,  wasps,  and  flies  which  stretched  along  the  line  of 
the  retreating  tide. 

This  suggests  the  fact  that  either  the  tadpoles  of  frogs,  or 
the  larvae  of  other  insects,  must  be  present  in  the  standing 
water  of  these  islands,  to  afford  food  to  the  voracious  larva? 
and  nymphs  of  these  dragon-flies. 

It  is  extremely  improbable  that  these  are  the  only  kinds  of 
Odonata  inhabiting  the  Bermudas.  The  swift-winged  ^Eschnas, 
and  some  of  the  large  and  strong  species  of  Tramea  and 
Libellula  have  been  seen  on  ships  at  a  greater  distance  from 
the  mainland  than  the  position  of  these  islands.  We  should 


156  THE  BERMUDA  ISLANDS. 

therefore  expect  to  find  such  forms  as  Anax  Junius,  T)*amca  Caro- 
lina, Pantala  flavescens,  and  perhaps  Libellula  scmifasciata  and 
Lepthemis  hsematogastra,  hawking  over  one  or  another  part  of 
the  low  districts  of  Bermuda,  and  especially  in  places  where 
mosquitoes  develop  in  greatest  numbers. 

DERMAPTERA. 

Labidura  riparia,  Pallas. 

Forfimla  gigantea,  Fab. 

A  few  specimens  of  the  male  of  this  large  and  showy  ear- 
wig are  present  in  the  collection.  Two  of  these  measure  10 
lines  to  the  end  of  the  abdomen,  while  the  chelee  have  a 
length  'of  fully  three  lines.  This  species  was  originally  de- 
rived from  the  region  of  the  Mediterranean,  but  it  has  recently 
been  widely  distributed  by  commerce  to  parts  along  the  eastern 
border  of  the  United  States,  and  no  doubt  the  same  agency 
has  transferred  it  to  the  soil  of  the  Bermudas. 

ORTHOPTERA. 
BLATTID.ffil. 

Blabera  Americana,  Linn. 

Several  specimens  both  of  the  adult  and  larval  form,  are  in 
the  collection.  They  differ  in  no  respect  from  the  usual  types 
which  are  now  distributed  over  most  of  the  world  by  the 
activities  of  commerce.  This  species  is  common  in  warehouses 
near  the  docks  in  some  of  our  cities  adjacent  to  the  Atlantic 
coast,  but  it  seems  not  to  have  formed  a  permanent  lodgment 
in  any  of  them.  The  supply  is  kept  up  by  the  frequent 
arrivals  of  vessels  from  tropical  countries,  in  which  they  rest 
concealed  between  the  packages  of  merchandise. 

Panchlora  Maderae,  Fab. 

This  is  another  common  cockroach  widely  distributed  by 
the  agency  of  commerce.  It  is  alluded  to  in  the  work  of  J.  M. 
Jones,  under  the  name  'Blatta  Maderensia,  as  being  seen  in 
"  cellars  and  '  other  dark  places,  on  these  islands,  where  it 
is  commonly  known  by  the  name  of  '  Knocker/  from  a  habit  it 


ZOOLOGY.     ARTHROPOD  A.  157 

has  of  making  a  noise  like  a  person  gently  tapping  a  box,  or 
skirting  board." 

ACRYDUDJE. 

Stenobothrus  maculipennis,  Scudder. 

A  pair  of  the  sexes,  from  which  the  colors  have  been  pretty 
thoroughly  extracted  by  the  alcohol,  is  present  in  this  collec- 
tion. In  points  of  structure  they  correspond  with  specimens 
common  to  the  region  around  Baltimore.  Yet  it  is  to  be  re- 
gretted that  the  entire  absence  of  original  color  and  conse- 
quent obscurity  of  pattern  of  marking  make  it  impossible  to 
ascertain  to  which  one  of  the  varieties  these  individuals  belong. 

o 

GRYLLID^J. 

Gryllus  luctuosus,  Serv. 

This  abundant  North  American  cricket  seems  to  be  well 
settled  upon  the  islands,  although  we  are  not  informed  as  to 
its  habits  and  distribution  in  that  locality.  It  is  the  most  lit- 
toral of  our  species  inhabiting  the  Atlantic  region,  and  finds  a 
home  in  all  the  States  from  eastern  Massachusetts,  on  Cape 
Cod,  to  the  neighborhood  of  Saint  Augustine,  Florida.  . 

Evidence  is  no  longer  wanting  as  to  the  modifications  in  the 
length  and  structure  of  the  wings  and  wing-covers  of  this 
species.  From  an  examination  of  one  colony  after  another  on 
one  of  the  beaches  south  of  Baltimore,  at  intervals  through  a 
period  of  more  than  twenty  years,  I  am  led  to  the  conclusion 
that  the  small  colonies  of  twenty  or  more  individuals  are  de- 
rived from  the  eggs  of  a  single  female.  Several  times  the  tide 
has  carried  off  and  drowned  all  the  individuals  from  a  short 
sand  beach,  which  had  to  be  re-stocked  by  another  brood  the 
succeeding  year.  By  aiding  in  this  work  through  the  intro- 
duction of  gravid  females  from  other  beaches,  I  have  essen- 
tially restored  the  original  condition  of  the  colony.  In  these 
assemblages  a  small  number  of  full-winged  individuals  occur 
almost  every  year,  and  during  times  in  which  the  beach 
becomes  clogged  by  excess  of  mud  or  carbonaceous  matter  the 
crickets-become  partly  darker  in  color.  A  great  advantage  is 


158  THE  BERMUDA  ISLANDS. 

gained  in  studying  this  species,  because  of  the  great  length  of 
its  ovipositor  and  the  greater  proportions  of  all  its  organs,  as 
compared  with  its  nearest  relatives  in  the  same  section  of 
country.  The  black  species  which  we  have  all  along  regarded 
as  Gryllus  Pennsylvanicus  Burm.  lives  almost  within  the  same 
territory,  but  it  prefers  the  dark  loamy  soils  farther  inland, 
and  only  ventures  upon  the  open  pale  sand  beaches  when 
hard  pressed  for  food  or  moisture. 

Further,  the  G.  luctuosus  is  very  variable  in  color  and  pat- 
tern of  marking  in  the  various  young  stages,  as  well  as  in  the 
fully  adult.  The  G.  Pennsylvanicus  on  the  other  hand  is  very 
slightly  variable  in  color,  and  has  a  much  shorter  ovipositor,  but 
it  also  has  occasional  individuals  of  both  sexes  fully  winged. 

Now  the  specimens  brought  in  from  Bermuda  display  pre- 
cisely the  same  differences  of  degree  and  kind  of  color  and 
structure  that  we  observe  belonging  to  those  colonies  inhabit- 
ing the  tidal  region  south  and  east  of  Baltimore.  From  Ber- 
muda the  long  and  short  winged  individuals  are  present  in 
both  sexes,  and  the  colors  vary  in  both  young  and  adults. 

LOCUSTIDJE. 

Orchelimum  vulgare,  Harris. 

A  badly  broken  female  specimen  is  the  only  representative 
of  this  form  in  the  collection.  The  length  and  form  of  the 
ovipositor  and  the  shape  and  markings  of  the  head  and  pro- 
notum  definitely  refer  it  to  this  species. 

DIPTERA. 
TABANIDJE. 

Tabanus,  sp.  ? 

This  is  one  of  the  smaller  horse-flies,  related  to  T.  lineola,  Fabr., 
but  in  color  it  resembles  the  T.  cincta,  Fabr.  The  specimens  are 
too  much  altered  to  be  accurately  determined. 

Odontomyia,  sp.  ? 

Two  specimens  are  in  the  collection. 

Sarcophaga  carnaria,  Linn. 

One  specimen  of  the  usual  type  is  present  in  the  collection. 


ZOOLOGY.     AKTHROPODA.  159 

A  CONTRIBUTION  TO  THE  KNOWLEDGE   OF  THE  SPIDER  FAUNA  OF  THE 
BERMUDA  ISLANDS. 

BY 
DR.  GEO.  MARX. 

Little  lias  been  heretofore  known  of  the  spider  fauna  of  the 
Bermudas.  Mr.  Blackwall  described  six  species  in  the  Ann. 
and  Mag.  of  Nat.  Hist.,  1868 ;  and  Prof.  E.  Simon,  in  speaking 
of  the  Arachnida  of  the  Atlantic  Islands  in  the  Annales 
Soc.  Entom.  de  France,  1883,  has  none  to  add  to  the  list  of  Mr. 
Blackwall.  He,  however,  alludes  to  the  character  of  the  Ber- 
muda spider  fauna  as  appearing  to  be  related  to  that  of  the 
Azores  and  the  Canary  Islands. 

Lately,  Prof.  Angelo  Heilprin,  of  Philadelphia,  visited  the 
Bermudas  and  collected  there  twelve  species,  and  by  his  kind- 
ness I  have  been  able  to  study  this  addition  to  the  spider 
fauna  of  that  region. 

Mr.  Blackwall  described  the  following  species: 

Loxosceles  rufescens,  Luc. 

Epeira  gracilipes,  Black w. 

Xysticus  pallidus,  Black  w. 

Salticus  diversus,  Black  w. 

Heteropoda  venatoria,  Linn. 

Filistata  depressa,  Koch. 

The  collection  of  Prof.  Heilprin  contains  the  following 
species : 

Uloborus  Zosis,  Walck. 

Nephila  clavipes,  Koch. 

Epeira  caudata,  Hentz. 

Epeira  labyrinthea,  Hentz. 

Theridium  tepidariorum,  Koch. 

Argyrodes  nepliilsc,  Taez. 

Pholcus  tipuloides,  Koch. 

Dysdera  crocata,  Koch. 

Menemerus  Paykullii,  Aud. 

Menemerus  melanognathus,  Luc. 


160  THE  BERMUDA  ISLANDS. 

Heteropoda  venatoria,  Linn. 
Lycosa  Atlantica,  nov.  spec. 

Loxosceles  ru/escens,  Luc.,  has  been  found  in  the  West  Indies, 
Central  America  and  Florida. 

Heteropoda  venatoria,  Linn,  seems  to  occur,  under  a  certain 
latitude,  everywhere  around  the  globe.* 

Filistata  depressa,  synonymous  (according  to  Simon)  with 
Filistata  capitata,  Hentz,  is  quite  common  in  the  southern  part 
of  the  United  States. 

Uloborus  Zosis,  Walck.,  is  recorded  from  the  West  India 
Islands,  Central  and  South  America,  and  occurs  also  some- 
times in  southern  Florida. 

Nepldla  clavipes,  Koch,  is  found  in  Brazil,  Central  America, 
Florida,  Texas,  and  Mississippi. 

Eperia  caudata,  Hentz,  inhabits  the  United  States  from 
Massachusetts  to  Georgia. 

Epeira  labyrinthea,  Hentz,  is  also  common  in  the  United 
States,  and  has  been  collected  in  the  West  Indies,  Central  and 
South  America,  as  far  south  as  the  Straits  of  Magellan,  and  in 
California. 

Theridium  tepidariorum,,  Koch,  is  common  to  Europe  and 
America. 

Argyrodes  nephilx  is  reported  from  Peru,  Cayenne  and  the 
Southern  States  of  the  United  States. 

Pholcns  tipuloides,  Koch,  has  been  described  by  this  author 
in  his  work  " Die  Arachniden  Australiens"  page  281,  from 
specimens  collected  at  the  Samoa  Islands. 

Dysdera  crocata,  Koch,  is  recorded  from  Greece,  France  and 
Germany,  and  is  also  common  in  the  United  States. 

Menemerus  Paykullii,  Aud.,  and  Menemerus  melanognathus, 
Luc.,  have  been  found  nearly  everywhere  on  the  globe. 

From  this  material  it  is  difficult  to  infer  the  true  character 
of  the  fauna  of  these  Islands.  The  frequent  arrival  of  vessels 

*See  an  article  by  Rev.  H.  C.  McCook,  in  Proceel.  Academy  Nat.  Sci.  Philad., 
1878. 


ZOOLOGY.    ARTHROPODA.  161 

from  many  foreign  ports,  the  drift  of  the  Gulf  Stream,  and 
other  causes,  have  introduced  into  this  region  a  number  of 
species  originally  foreign  to  that  locality,  but  which,  in  time, 
not  only  have  acclimatized  themselves,  but  have,  in  a  more 
or  less  marked  degree,  driven  away  and  extinguished  the  in- 
digenous spider  fauna. 

This  fact  has  been  noticed  in  all  localities  open  to  the  im- 
portation of  a  foreign  element.  These  species  are  then  called 
cosmopolitan,  and. by  far  the  greater  number  of  those  brought 
to  notice  by  Mr.  Blackwall  and  Prof.  Heilprin  bear  this  char- 
acter; but  drawing  a  superficial  conclusion  from  this  material 
it  seems  that  the  spider  fauna  of  the  Bermudas  is  more 
American  than  anything  else,  for  out  of  the  seventeen  species 
now  known,  only  four  are  original  (so  far)  to  these  Islands,  and 
nine  are  found  also  in  the  limits  of  the  United  States. 

Lycosa  Atlantica,  nov.  spec. 

Cephalothorax  dark  olivaceous  brown,  with  a  narrow  longi- 
tudinal yellow  band  over  the  middle,  which  begins  at  the  pos- 
terior margin  and  runs  over  the  whole  length  into  the  region 
of  the  first  eye  row.  Another,  equally  colored,  but  somewhat 
broader,  band  runs  at  the  sides,  above  the  lateral  margin,  ter- 
minating at  the  sides  of  the  pars  cephalica.  Mandibles  dark 
brown  with  long,  thick,  and  black  pubescence.  Maxillae  and 
labium  more  reddish  brown ;  sternum  lighter,  olivaceous  yel- 
low with  a  lighter  border,  hairy.  Palpi  and  legs  uniformly 
light  olivaceous  yellow,  with  black  hairs  and  without  rings  or 
markings,  tarsal  joints  of  the  former  infuscated.  Abdomen : 
dorsum  dark  olivaceous  brown  with  a  narrow,  whitish,  slightly 
spear-shaped  figure,  which  is  edged  by  a  very  narrow  blackish 
line;  behind  this  a  row  of  four  rather  indistinct  white  (small) 
round  spots,  which  reach  the  apex.  Venter  light  yellow,  mid- 
dle region  still  lighter. 

Cephalothorax  as  long  as  patella  X,  tibia  IV;  one-third 
longer  than  wide ;  back  straight,  evenly  sloping  in  back  and 
front,  face  nearly  perpendicular.  Lower  eye  row  longer  than 


162      \  THE  BERMUDA  ISLANDS. 

second.  Middle  eyes  of  lower  row  about  twice  as  large  as  the 
lateral  eyes.  Distance  between  the  large  eyes  of  the  second 
row  smaller  than  their  diameter;  eyes  of  the  third  row  as 
large  as  middle  ones  of  the  first  row.  Mandibles  as  long  as 
tibia  III.  Cephalothorax  long,  6  mm.;  broad,  4*5  in  the  mid- 
dle region  ;  in  front,  2'2. 

Abdomen,  long,  6  mm.     Mandibles,  27. 

Femur  I      4  Patella  2  Tibia  8-3  Metatarsus  2-8  Tarsus  2'2  Total,  14"3 

"       II    38  "2           "3                "          2-7            "      2  "      13."> 

"       III  3-4  "      1-8        "     2-8              "          3               "      1-5  "      12  5 

"       IV  5  "      2-1         "      4                 "          5-5            "      2-4  "      19 

EXPLANATION  OF  PLATE  14. 

Fig.  1.  Uloborus  Zosis,  Walck.     Female. 

l.a.     Abdomen  from  the  side. 

l.b.     Epigynum. 

I.e.     Male  palpus. 
Fig.  2.  Menemerus  Paykullii,  Aud. 


NOTES  ON  A  SMALL  COLLECTION  OF  MYRIAPODS  FROM  THE 
BERMUDA  ISLANDS. 

BY 
CHARLES  H.  BOLLMAN. 

The  following  species,  which  were  collected  by  Prof.  Heil- 
prin  in  the  Summer  of  1888,  although  limited  in  number, 
show  the  diverse  origin  of  the  myriapod  fauna  of  the  Bermuda 
Islands.  Heretofore,  Julus  Moreleti  had  only  been  found  in  the 
Azores  Islands ;  Mecistocephalus  Guildingii  in  the  West  Indies ; 
Lithobius  lapidicola  in  Europe;  and  Spirobolus  Heilprini,  by 
having  scobina,  shows  its  West  Indian  and  not  African  origin, 
for  all  the  Spiroboli  found  in  the  latter  continent  belong  to  the 
subgenus  from  which  scobina  are  absent. 

These  four  species,  besides  a  specimen  of  Scolopendra  sub- 
spinipes  which  I  have  in  my  collection,  are  all  that  have  a?  yet 
been  reported  from  the  Bermuda  Islands. 

Spirobolus  Heilprini,  sp.  nov. 


ZOOLOGY.    ARTHROPODA.  163 

Diag. — Related  to  Spirobolus  flavocmctus,  Karsch.,  but  the 
segments  very  distinctly  segmented  ;  anterior  part  not  striate ; 
antennae  and  legs  reddish-brown. 

Type. — Museum  Acad.  Nat.  Sci.  Phil.  Greenish -black,  pos- 
terior margin  of  segments  rufous;  antenna  and  legs  reddish- 
brown.  Slender,  anterior  segments  scarcely  attenuated.  Ver- 
tex smooth,  sulcus  shallow;  clypeus  only  moderately  emargin- 
ate,  foveote  2  +  2,  distant ;  sulcus  sub-continuous  with  verti- 
cal. Antennee  rather  slender,  reaching  second  segment  in 
both  sexes.  Ocelli  arranged  in  a  suboval  or  subtriangular 
patch,  45-55,  in  seven  or  eight  series.  Segments  not  smooth  ; 
posterior  parts  above  with  short  and  wavy  strire,  beneath  with 
short  and  straight  strise ;  median  part  with  a  transverse  sulcus 
which  ends  above  repugnatorial  pore;  posterior  above  with 
a  few  stria?,  beneath  almost  smooth  or  with  a  few  weak  oblique 
strise.  Lateral  lobes  of  first  segment  rounded,  a  weak  mar- 
ginal sulcus.  Anal  segment  with  a  flat,  thick  mucro,  which 
passes  beyond  valves;  anal  valves  weakly  margined,  not 
punctate;  anal  scale  obtusely  angled.  Repugnatorial  pore 
placed  on  anterior  division,  small  and  rather  deeply  set,  Legs 
extending  slightly  beyond  sides  of  body.  Male:  slenderer 
than  female;  coxa?  of  3d,  4th,  and  5th  pairs  of  legs  produced 
into  short  lobes ;  .tibia  and  first  two  tarsal  joints  beneath  with 
an  oval  roughened  lobe ;  joints  of  anterior  legs  short  and  thick, 
third  and  fourth  pairs  of  legs  strongest ;  tarsi  without  a  pad  ; 
ventral  plate  of  copulation-foot  triangular,  as  high  as  foot,  its 
base  not  concave,  its  posterior  surface  ridged,  thus  making  the 
plate  of  a  triangular-pyramidal  form ;  anterior  part  of  first 
foot  not  as  high  as  ventral  plate,  triangularly  pointed,  the  ven- 
tral plate  ridge  separating  them  ;  posterior  part  of  anterior 
foot  as  high  as  ventral  plate,  its  apex  with  a  short  blunt  lobe 
on  its  posterior  surface ;  posterior  copulation-foot  bifid,  pro- 
jecting out  of  the  opening,  the  upper  branches  flattened  and 
fan-shaped  at  the  end,  which  is  convex  ;  lower  branch  elongate- 
lanceolate,  its  upper  edge  serrate  ;  basal  part  of  foot  rectangular 
and  white,  while  the  upper  part  is  yellowish. 


164  THE  BERMUDA  ISLANDS. 

Segments  male,  46 ;  female,  44. 

Length  52mm,  width  3'8min- 4'2mra 

This  species  is  described  from  six  broken  and  badly  pre- 
served specimens.  In  the  type  of  copulation-foot  it  resembles 
S.  arbor eus  and  S.  Dugesi,  and  it  is  very  probable  that  all 
the  species  belonging  to  this  group  have  the  same  type,  i.e.  the 
ventral  plate  triangular  and  as  high  as  posterior  part  of  an- 
terior part,  while  the  anterior  part  is  less,  the  posterior  foot 
bifid  and  projecting  out  of  the  opening. 

I  have  named  this  species  after  Prof.  Angelo  Heilprin,  of  the 
Academy  of  Natural  Sciences  of  Philadelphia. 

Julus  Moreleti,  Lucas. 

In  the  collection  are  a  number  of  female  specimens  which 
I  refer  to  this  species.  It  has  only  been  found  in  the  Azores 
Islands. 

These  specimens  have  the  striae  of  the  anterior  division  of 
the  segments  not  so  irregular  as  is  represented  in  Porath's  figure 
of  the  species.* 

Segments  42-49.  Adult  almost  black,  legs  reddish-brown ; 
young  dusky,  with  a  lateral  row  of  black  spots  and  a  medium 
black  dorsal  line,  bordered  with  yellowish. 

Mecistocephalus  Guildingii,  Newport. 

Three  specimens.  These  are  so  moulded  and  broken  that 
it  is  almost  impossible  to  make  much  out  of  them  ;  but  in  the 
characters  of  the  head  they  seem  to  be  identical  with  the  West 
Indian  species. 

Lithobius  lapidicola,  Meinert. 

Two  specimens,  male  and  female.  Joints  of  antennae  26 ; 
ocelli  8  or  9,  in  three  series;  coxal  pores  male  2,  3,  3,  2,  female 
3,  4,  4,  3;  spines  of  first  pair  of  legs,  0,  1,1;  of  penultimate 
pair,  1,  3,  3,  1 ;  of  anal  pair,  1,  3,  2,  0;  spines  of  female  geni- 
talia  stout,  claw  very  distinctly  tripartite,  middle  lobe  not 
much  the  longest;  length  male  7mm;  female  8ram. 

*Am   nagra   Myriopoder   frlu    Azorerna.       Ofver.    Kongl.    Vet.    Akad.    Forh. 
Stockh.,  820,  1870. 


ZOOLOGY.     ARTHROPOD  A.  165 

It  is  very  possible  that  these  specimens  are  not  identical 
with  L.  lapidicola,  a  European  species ;  but  as  they  are  rather 
mutilated,  I  have  hesitated  to  describe  them  as  new. 


IX. 


ZOOLOGY  OF  THE  BERMUDAS  (continued). 


MOLLUSCA. 

The  species  of  mollusks  enumerated  in  the  following  pages, 
although  probably  far  short  of  the  actual  number  found  in 
the  region,  give  a  good  idea  of  the  character  of  the  mollus- 
can  fauna  of  the  archipelago.  Somewhat  more  than  170 
marine  forms,  and  30  terrestrial  species,  are  catalogued  ;  before 
our  visit  barely  more  than  one-half  of  this  number  had  been 
officially  recorded  from  the  Bermudas.  The  general  relation- 
ship of  this  fauna  has  already  been  discussed  in  Chapter  V, 
and  it  is,  therefore,  not  necessary  to  enter  here  into  any  further 
details  connected  with  the  subject. 

CEPHALOPODA. 

Cuttle  fishes  are  said  to  be  abundant  in  the  Bermudian 
waters,  but  we  were  not  very  successful  in  our  search  after 
these  animals.  Two  moderately  large  octopods,  which  we 
could  only  see,  but  not  obtain,  may  possibly  be  the  common 
West  Indian  Octopus  vulgaris,  or  one  of  the  forms  that  have 
been  separated  off  from  it  as  a  distinct  species.  We  made 
considerable  efforts  to  capture  one  of  these,  but  all  our  at- 
tempts to  dislodge  the  creature  from  its  hold  upon  the  interior 
of  a  rock-crevice  were  unvailing.  The  following  species 
(Octopus  chromatus)  was  obtained  beneath  a  stone  on  the  beach 
of  Flatts  Village, 


ZOOLOGY.     MOLLUSCA.  167 

Octopus  chromatus,  n.  sp. 
Argonauta. 

It  seems  to  me  likely  that  at  least  two  forms  of  the  argonaut 
are  found  here — Argonauta  hians  and  A.  Argo.  Unfortunately 
I  am  compelled  to  rely  upon  my  memory  alone  for  the  de- 
termination of  these  forms,  and  possibly  I  may  be  in  error. 
The  animal  or  parts  of  the  animal  of  the  argonaut  have  been 
several  times  captured  on  the  Bermudian  shores,  and  Mr.  Bar- 
tram,  of  Stock's  Point,  has  a  beautifully  preserved  specimen 
of  one  of  the  species  that  was  caught,  I  believe,  some  forty 
years  ago,  or  more. 

Spirula  Peronii,  Lam. 

The  shell  of  this  cephalopod  is  very  abundant,  and  may  be 
found  largely  gathered  in  with  the  strewn  Gulf-wrack  which 
in  most  places  lines  the  coast.  The  shells  are  also  found  in 
quantities,  a  half  dozen  or  more,  in  the  tidal  rock-cavities, 
whither  they  had  been  swept  by  the  sea. 

GASTEROPODA.* 

Murex  erosus,  Brod. 

La  Paz,  Panama. 

Murex  nuceus,  Morch. 

This  species  was  originally  described  from  the  Bermudas. 
An  identical  form  from  Marco,  west  coast  of  the  peninsula  of 
Florida,  is  in  the  collections  of  the  Academy  of  Natural 
Sciences  of  Philadelphia. 

Purpura  deltoidea,  Lam. 

Fla.,  Bahamas. 

Purpura  haemastoma,  L. 

var.     P.  undata,  Lam. 
P.  bicostalis. 

Forida,  W.  Indies. 

*  The  localities  mentioned  indicate  in  a  general  way  the  range  of  the  species.1 


168  THE  BERMUDA  ISLANDS. 

Sistrum  nodulosum,  Ads. 

Florida,  Aspinwall. 

Triton  cynocephalus,  Lam. 

St.  Thomas,  Philippines. 

Triton  pileare,  L. 

W.  Indies,  Philippines. 

Triton  chlorostoma,  Lam. 

W.  Indies,  Mauritius,  Philippines. 

Triton  tuberosum,  Lam. 

W.  Indies,  Mauritius,  Society  Is. 

Epidromus  concinnus,  Reeve. 

Philippines. 

This  species,  the  specimens  of  which  are  absolutely  identi- 
cal with  the  forms  from  the  Philippine  Islands,  is  closely  re- 
lated to  Tryon's  Epidromus  Swifti,  from  Antigua,  but  the  ribs 
are  less  prominent  than  in  that  species,  and  the  general  out- 
line of  the  shell  is  more  acicular. 

Epidromus  (Triton)  lanceolatus,  Menke. 

I  give  this  species  on  the  authorit}'  of  Matthew  Jones  (Con- 
tributions to  the  Natural  History  of  the  Bermudas,  Trans. 
Nova  Scotia  Inst.) 

Eanella  cruentata,  Sow. 

var.     R.  Rhodostoma,  Beck. 
R.  Thomse,  D'Orb. 

St.  Thomas,  Mauritius,  Philippines. 

Fasciolaria  distans.  Lam. 

I  did  not  myself  meet  with  this  shell.  Jones  obtained 
a  single  specimen,  partly  imbedded  in  the  calcareous  rock, 
and  it  is  therefore  not  unlikely  that  the  animal  is  still  an  in- 
habitant of  the  surrounding  waters. 

Leucozonia  cingulifera,  Lam, 

Florida, 


ZOOLOGY.    MOLLUSC  A.  169 

Hemifusus  morio,  L. 

Martinique,  W.  Africa. 

?  Pisania  biliratum,  Reeve. 

I  have  little  doubt  that  the  species  occurring  under  this 
name  in  Jones's  list  is  a  Cantharus. 

Cantharus  Coromandelianus,  Lam. 

W.  Indies. 

Cantharus  tincta,  Cour. 

Florida. 

Phos,  sp.  ? 

Two  young  specimens  which  I  have  been  unable  to  identify 
with  known  species. 

Nassa  ambigua,  Montf. 

W.  Indies. 

Marginella  apicina,  Menke. 

Florida,  Bahamas. 

Marginella  minuta,  Pfr. 

Bahamas. 

Volvaria  avena,  Valenc. 

Florida,  \V.  Indies. 

T  Volvaria  pellucida, 
Olivella  oryza,  Lam. 

W.  Indies. 

Olivella  nivea,  Gmel. 

W.  Indies. 

These  two  are  probably  one  species. 

?  Olivella  miliola 
Oliva  reticularis,  Lam. 

Florida,  W.  Indies,  Venezuela. 

?  Oliva  bullula,  Sow. 

The  species  marked  with  this  name  in  Jones's  list  is  prob- 
ably Olivella  oryza  or  0.  nivea. 


170  THE  BERMUDA  ISLANDS. 

Dall,  in  his  list  of  the  West  Atlantic  marine  Mollusca  (Bull. 
U.  S.  National  Museum,  No.  24,  1885),  includes  Oliva  mutica, 
Say,  among  his  Bermudian  species,  and  quotes  Krebs  as  his 
authority.  This  is  an  error.  Krebs  makes  no  mention  of  the 
occurrence  of  the  species  in  the  Bermudas  (Catalogue  West 
Indian  Marine  Shells,  p.  39). 

Columbella  mercatoria,  L. 

W.  Indies. 

Columbella  cribraria,  Lam. 

Florida,  Bahamas. 

Columbella  (Anachis)  sp.    ? 

A  form  closely  allied  to  A.  plicaria,  from  New  Caledonia. 

Cythara  (Pleurotoma),  n.  sp. 

Identical  with  a  form  from  Key  Largo,  Florida. 

Conus  Agassizii,  Dall. 
Strombus  gigas,  L. 

Florida,  W.  Indies,  S.  America. 

Strombus  accipitrinus,  Mart. 

W.  Indies. 

All  the  specimens  of  this  species  that  I  have  seen  from  the 
Bermudas  lack  the  epidermis,  and  have  the  columellar  sur- 
face of  a  leaden,  gray  color.  They  seem  to  differ  from 
the  normal  type  of  the  species  in  having  a  broader  and  more 
elevated  spire,  and  in  a  more  regular  nodulation  of  the  body- 
whorl. 

Cypraea  cervus,  L. 

W.  Indies,  Panama. 

This  species  grows  to  a  very  large  size.  A  specimen  which 
I  had  the  privilege  of  examining  in  the  collection  of  Mr.  Bar- 
tram,  of  Stock's  Point,  far  surpasses  in  this  respect  all  other 
specimens  of  the  species  which  have  come  to  my  notice.  The 
species  occurs  as  a  sub-fossil  at  St.  George's  and  elsewhere. 


ZOOLOGY.     MOLLUSCA.  171 

Cypraca  cinerea,  Gmel. 

Also  occurs  as  a  sub-fossil. 

Trivia  quadripunctata,  Gray. 

Bahamas. 

Trivia  suffusa,  Gray. 

Bahamas. 

I  believe  that  these  two  forms  are  merely  varieties  of  one 
and  the  same  species,  being  connected  by  a  number  of  inter- 
mediate types. 

Cyphoma  gibbosa,  L. 

Florida,  Cuba. 

Dolium  perdix,  L. 

W.  Indies,  Pacific  Islands. 

Natica  canrena,  L. 

Florida,  W.  Indies,  Costa  Rica. 

The  nidus  of  probably  this  species,  which  we  found  in  the 
Flatts  Inlet,  is  a  collar  of  lime-mud,  in  form  very  much  like 
that  of  Natica  heros,  of  the  east  American  coast. 

Natica  lactea,  Guild. 

This  species  is  very  close  to,  if  not  identical  with,  Natica 
Flamingiana,  Reel.,  from  the  Feejee  Islands. 

Natica  Marochinensis,  Gmel. 

W.  Indies,  W.  Africa,  Sandwich  Islands. 

Crepidula  convexa,  Say. 

Eastern  United  States. 

Two  small  specimens  obtained  through  the  kindness  of  Miss 
A.  Peniston,  which  are  seemingly  this  species. 

1  Crepidula  fornicata,  L.    (young.) 
Phorus  agglutinans,  L. 

This  is  probably  a  rare  shell.  We  obtained  but  a  single 
specimen  from  the  rocks  off  Bailey's  Bay. 


172  THE  BERMUDA  ISLANDS. 

Adeorbis. 

A  number  of  small  specimens,  obtained  from  the  sands  of 
the  north  shore,  which  closely  resemble  the  Helix  (Adeorbis) 
cyclostomoides  of  Pfeiffer,  from  Cuba.  The  spire  in  the  Bermu- 
dian  form  is,  however,  practically  wanting. 

Scalaria  clathrus,  L. 

S.  lamellosa,  Lam. 

8.  coronata. 

South  Carolina,  W.  Indies,  Europe. 

lanthina  communis,   Lam. 

Florida. 

Common  on  both  shores  of  the  islands,  and  largely  associated 
with  Spirula  Peronii.  Its  occurrence  away  from  the  immediate 
shore-line  is,  doubtless,  due  to  wind  deposit. 

lanthina  globosa,  Swn. 

Florida. 

This  species  is  apparently  much  less  abundant  than  the 
preceding. 

Turritella,  sp.  ? 

Several  fragments  of  a  species  which  I  have  been  unable  to 
determine. 

Petaloconchus,  sp.  ? 
?  Vermetus  Knorri,  Say. 

fVermetus  radicula,  Stimpson. 

Siliqnaria  (Tenagodus)  ruber,  Schura. 

I  give  this  species  as  a  member  of  the  Bermudian  fauna  on 
the  authority  of  Morch. 

Caecum  Floridanum,  Stimps. 

Florida. 

A  single  specimen  from  the  sands  of  the  north  shore. 

Caecum  termes.  n.  sp. 

A  number  of  specimens  obtained  through  the  kindness  of 
Miss  Peniston, 


ZOOLOGY.    MOLLUSCA.  173 

T  Eulima  Jamaicensis,  Adams. 

W.  Indies. 

Leiostraca.  sp.  ? 
Sty  lifer,  sp.  ? 

Abundant  in  the  skin  of  the  large  holothurians  (Stichopus). 
I  failed  to  obtain  specimens,  and  am,  in  consequence,  ignorant 
of  the  species. 

Turbonilla  pulchella,  D'Orb. 

Chemnitzia  pulchella,  D'Orb. 
St.  Thomas. 

Turbonilla  pusilla,  Adams. 

St.  Thomas. 

Littorina  zic-zac,  Chemn. 

Bahamas,  Cuba. 

Littorina  angulifera,  Lam. 

Littorina  lineata,  Gmel. 
et.  L.  scabra,  L.  ? 
W.  Indies. 

Littorina  muricata,  L. 

W.  Indies. 

Littorina  Mauritiana,  Lam. 
Tectarius  Antillarum,  D'Orb. 

W.  Indies. 

Modulus  Floridanus,  Conr. 

Florida. 

The  Modulus  lenticularis  (Chemn.)  of  Jones  is  probably  this 
species. 

Modulus  pisum,  Beck. 

Placed  here  on  the  authority  of  Morcb. 

Litiopa  striata,  Rang. 
Cerithium  literatum,  Brug. 

W.  Indies. 


174  THE  BERMUDA  ISLANDS. 

Cerithium  ferrugineum,  Say. 

C.  versicolor,  Adams. 
C.  Bermudas,  Sowb. 
(7.  Eriense,  Val. 
Florida,  W.  Indies. 

Cerithium,  sp.  ? 

A  form    apparently  closely  related  to    Cerithium   diadema, 
Watson,  from  Madeira. 

Potamides  minimus,  Grnel. 

P.  nigrescens,  Menke. 

P.  alboviUatue,  Adams. 

?P.  zonale  (in  part),  Drug. 

E.  United  States,  W.  Indies,  Europe. 

Triforis  turris-Thomae,  Chemn. 

St.  Thomas. 

Triforis  inter medius,  Adams. 

St.  Thomas. 

Bissoina  crassicostata.  Adams. 

St.  Thomas. 

Rissoina  Sagraiana,  D'Orb. 

St.  Thomas. 

Rissoina  micans,  Adams,  in  Jones's  list 

Hydrobia  1 

Nerita  peloronta,  L. 

W.  Indies. 

Nerita  tessellata,  Gmel. 

W.  Indies. 

Nerita  versicolor,  Gmel. 

Florida,  W.  Indies,  Costa  Rica. 

Neritina  viridis,  L. 

W.  Indies,  Lancerote,  Mediterranean. 


ZOOLOGY.    MOLLUSCA.  175 

Neritina  Virginea,  L. 

W.  Indies,  Brazil. 

Phasianella  Kochi,  Phil. 

South  Africa.    . 

This  species   is   not  unlikely  but  a  variety  of  Phasianella 
pulla,  L.,  from  the  Mediterranean,  the  west  coast  of  Africa,  etc. 

Turbo  pica,  L. 

W.  Indies,  Nicaragua,  Panama. 

This  large  and  beautiful  shell  is  abundant  along  the  south- 
ern shores,  where  it  also  occurs  imbedded  as  a  sub-fossil  in  the 
calcareous  rock.  It  appears  to  be  always  largely  water-worn, 
and  in  no  instance  did  it  contain  the  animal.  Indeed,  I  am 
assured  by  old  residents  who  have  intentionally  sought  for  the 
animal  that  it  has  never  been  found  in  the  island-waters. 
Probably  the  animal  inhabits  the  deeper  waters,  and  only  the 
empty  shell  is  cast  upon  the  beach. 

Astralium  longispina,  Lam. 

Trochus  (Imperator)  calcar,  L.,  of  Jones's  list. 
W.  Indies,  Honduras. 

Stomatia  picta,  D'Orb. 

St.  Thomas. 

Fissurella  viridula,  Lam. 

W.  Indies. 

Fissurella  Barbadensis,  Ginel. 

Barbados. 

Fissurella  Antillarum,  D'Orb. 

Cuba. 

Fissurella  alternata,  Say. 

Eastern  United  States,  Nicaragua. 

Emarginula  dentigera,  n.  sp. 
Emarginula  pileum,  n.  sp. 


176  THE  BERMUDA  ISLANDS. 

Patella  notata,  Lam. 

Patella  confusa. 
W.  Indies. 

Bulla  striata,  Brug. 

Florida,  W.  Indies,  Africa,  etc. 

Bullina  (Bulla)  nitidula,  Dillw. 
Hydatina  (Bulla)  physis,  L. 

These  two  West  Ridian  species  are  here  enumerated  on  the 
authority  of  Jones. 

TJtriculus  Candei,  D'Orb. 

Florida,  W.  Indies. 

Umbrella  (Operculatum)  Bermudensis,  Morch. 

On  the  identification  of  Morch. 

Siphonaria  picta,  Sow. 

Panama,  Mazatlan. 

*  Siphonaria  alternata,  Say. 

Florida. 

Dentalium  semistriatum,  Guild. 

W.  Indies. 

Cadulus  quadridentatus,  Dall. 

Florida  coast. 

Chiton  squamosus,  L. 
Chiton  marmoratus,  Gmel. 
Ischnochiton  purpurascens,  Adams. 
Tonicia  Schrammi,  Shuttl. 
Aplysia  aeqnorea,  n.  sp. 
Chromodoris  zebra,  n.  sp. 

LAMELLIBRANCHIATA. 
Teredo,  sp.  ? 

Found  in  driftwood  ;  species  undetermined. 


ZOOLOGY:    MOLLUSCA.  17? 

Martesia  striata,  L. 

On  the  authority  of  Jones. 

Siliqua  bidentata,  Spengl. 

Florida,  Panama. 

Macha  Antillarum,  D'Orb. 
Lyonsia  Beaui,  D'Orb. 
Florida,  W.  Indies. 

Semele  variegata,  Lam. 

Florida. 

Semele  orbiculata,  Sow. 

Florida,  S.  Car.,  W.  Indies. 
?  Semele  reticulala,  Say. 

Semele  cancellata,  Sow. 

St.  Thomas. 

Asaphis  coccinea,  Martyn. 

W.  Indies. 

Strigilla  flexuosa,  Say. 

W.  Indies. 

Tellina  polita,  Say. 

East  coast  America,  Florida. 

Tellina  Gouldii,  Hanley. 

California. 

Tellina  Tampseensis,  Conr.,  from  Florida,  is  probably  identi- 
cal with  this  species:  but  there  is  no  question  as  to  the  identity 
of  the  Bermudiaii  and  California!!  forms. 

Tellina  Gruneri,  Phil. 

Tellina  intastriata,  Sa"y. 

Capsa  spectabilis  of  Jones's  list. 

St.  Thomas. 

Tellina  radiata,  L. 

and  var.  Tellina  unimaculata. 
W.  Indies. 


178  THE  BERMUDA  ISLANDS. 

Tellina  interrupta,  Wood. 

Tellina  maculosa,  Lam. 
St.  Thomas. 

Tellina  laevigata,  L. 

Bahamas. 

Tellina  magna,  Spengl. 

Florida,  W.  Indies. 

Tellina  exilis,  Lam. 

Guadeloupe,  Jamaica. 

Macoma  eborea,  n.  sp. 
Chione  Venetiana,  Lam. 

St.  Thomas,  France. 

Circe  Cubaniana,  D'Orb. 

Florida,  W.  Indies. 

Venus  cancellata,  L. 

Given  on  the  authority  of  Jones. 

Cytherea  Penistoni,  n.  sp. 
Cardium  serratum,  Brug. 

Florida,  St.  Thomas. 

Cham  a  macrophylla,  Cheinn. 

W.  Indies. 

Chama  exogyra,  Conr. 

California,  Mexico. 

Two    specimens,   which    are   absolutely   un  distinguish  able 
from  the  species  of  the  west  American  coast. 

Chama  lingua-felis,  Reeve. 
Chama  Bermudensis,  n.  sp, 
Lucina  edentula,  L. 

Loripes  chrysostoma  of  Jones's  list. 
Florida,  W.  Indies,  Nicaragua. 

Lucina  squamosa,  Lam. 


ZOOLOGY.   MOLLUSCA.  ite 

?  Lncina  imbricatula,  Adams. 
W.  Indies. 

Lucina  tigrina,  L. 

W.  Indies. 

Lucina  imbricatula,  Adams. 

W.  Indies,  Aspinwall. 

Lucina  Antillarum,  Reeve. 

Lucina  costata,  D'Orb. 
W.  Indies. 

Lucina  obliqua,  Reeve. 

Lucina  pcctinata,  Ads. 
St.  Thomas. 

Mysia  pellucida,  n.  sp. 

A  form  identical  with  the  above,  from  St.  Thomas,  is  con- 
tained in  the  collections  of  the  Academy  of  Natural  Sciences. 

Crassatella  Guadelupensis,  D'Orb. 

W.  Indies. 

Area  Noae,  L. 

W..  Indies,  Europe. 

Area  Deshayesii,  Hanley. 

St.  Thomas. 

I  have  no  doubt  that  the  Area  Americana,  of  Gray,  men- 
tioned by  Jones  as  a  very  common  shell  of  the  Bermudas,  is 
this  species. 

Area  gradata.  Brod. 

Area  Domingensis,  Lam. 

Florida,  St.  Thomas,  Mazatlan,  Cape  Verde  I. 

Area  Adamsi,  Shuttl. 

Florida,  Cuba. 

The  Bermudian  specimens  appear  to  be  somewhat  less  pro- 
duced posteriorly  than  the  more  southern  forms,  but  in  other 
respects  they  agree  very  closely.  The  species  is  probably 


180  THE  BERMUDA  ISLANDS. 

identical  with  Area  solida,  B.  and  S.,  from   the   Californian 
coast. 

Area  imbricata,  Brug. 

W.  Indies,  Mazatlan,  Feejee  Islands. 

The  Area  mutabilis,  of  Sowerby,  does  not  differ  essentially 
from  this  species. 

Mytilus  exustus,  L. 

Mytilus  Domingensis  of  Jones's  list. 
Modiola  tulipa,  L. 

E.  United  States,  Bahamas,  W.  Indies. 

Lithodomus  Antillarum,  Phil. 

Litltodomus  niger. 
Florida,  St.  Thomas. 

Lithodomus  appendioulatus,  Phil. 

Cuba. 

Crenella  lateralis,  Say. 

S.  Carolina,  Florida. 

Avicula  ala-perdicis,  Reeve. 

Meleagrina  placunoides,  Reeve,  of  Jones's  list. 
Florida,  W.  Indies. 

Avicula  Atlantioa,  Lam. 

S.  Carolina. 

?  Avicula  macroptera,  Lam. — W.  Indies,  E.  Indies. 

Perna  ephippium,  L. 

Antilles,  Indian  and  Pacific  Oceans. 

Pinna  rudis,  Lain. 

W.  Indies. 

Plicatula  ramosa,  L. 

Florida,  W.  Indies. 

Lima  tenera,  Chemn. 

Lima  fragilis,  Sow.,  of  Jones's  list. 
Florida. 


ZOOLOGY.    MOLLUSCA.  181 

Pecten  zig-zag,  L. 

W.  Indies,  Pacific  Ocean. 

Pecten  imbricatus,  Gmel. 

St.  Thomas,  Pacific  Ocean,  Australia. 

Spondylus  Americanus,  Lain. 

W.  Indies. 

There  seems  to  be  much  confusion  regarding  the  species  of 
Spondylus  which  inhabit  the  West  Indian  and  Bermudian 
waters,  and,  as  it  appears  to  me,  an  unnecessary  multiplication 
of  specific  names.  The  individual  variation  among  the 
species  is  very  great,  and  does  not  permit  of  that  close  charac- 
terization of  forms  which  has  been  attempted  by  some  syste- 
matists.  I  believe  that  Spondylus  Americanus  includes  much, 
if  not  all,  of  what  has  been  described  under  Spondylus  longi- 
tudinalis,  S.  ustulatus,  S.  coccincus,  and  S.  erinaceus. 

Anomia  ephippium,  L. 

America,  Europe. 

Ostrea  frons,  L. 

W.  Indies. 

PULMONATA. 

The  land  shells  enumerated  in  the  following  list  are  in  ex- 
cess by  some  ten  forms  of  the  number  hitherto  credited  to  the 
Bermudas.  Most  of  these  we  collected  ourselves  or  obtained 
through  the  aid  of  local  collectors;  others  I  found  in  the  col- 
lection made  a  few  years  ago  by  Mr.  G.  Brown  Goode,  while  a 
few  have  been  quite  recently  sent  to  me  by  Miss  A.  Peniston, 
of  Peniston's,  Bermuda.  The  remaining  forms  are  given  on 
the  authority  of  Fischer  (Manuel  de  Conchy  liologie),  Bland 
(quoted  by  Wallace  in  "  Island  Life,"  pp.  256-57),  and  Pfeiffer. 
These  are  preceded  by  an  asterisk.  For  the  determination  of 
the  species  I  am  largely  indebted  to  Mr.  H.  A.  Pilsbry,  Conserva- 
tor of  the  Conchological  Department  of  the  Academy  of  Natural 
Sciences,  who  has  also  prepared  a  special  paper  on  the  more 


182  THE  BERMUDA  ISLANDS. 

distinctive  Bermudian  Helices.  The  localities  placed  opposite 
the  species  indicate  in  a  general  way  their  geographical  dis- 
tribution. 

Helix  (Cochlicella)  ventricosa,  Drap. 

Mediterranean  region,  Canaries,  Azores. 

Helix  (Microphysa)  vortex,  Pfr. 

W.  Indies,  S.  United  States. 

Helix  (Polygyra)  microdonta,Desh. 

Texas,  Florida? 

Helix  (Hyalosagda)  discrepans,  Pfr. 

*  Helix  (Vallonia)  pulchella,  MU11. 

Europe,  Azores. 

Given  on  the  authority  of  Bland,  as  quoted  by  Wallace.  This 
species  appears  to  differ  but  little,  if  at  all,  from  Helix  rfiinuta, 
of  Say,  a  common  form  of  the  United  States. 

Helix  appressa,  Say. 

Pennsylvania  to  Illinois  and  Arkansas. 

?  Helix  hypolepta,  Shuttl. 

This  species,  which  appears  to  have  been  obtained  from  the 
Bermudian  collection  of  M.  Bland,  is  very  inadequately  de- 
scribed by  Shuttleworth  (Diagnosen  neuer  Mottusken,  p.  129),  so 
that  it  is  barely  recognizable  as  a  distinct  species.  It  is  closely 
related  to  Helix  minuscula,  of  Binney, 

Poecilozonites  Bermudensis,  Pfr. 
Poecilozonites  circumfirmatus,  lledf, 
Poecilozonites  Reinianus,  Pfr. 
Succinea  Bermudensis,  Pfr. 

*  Succinea  fulgens,  Lea. 

Cuba. 

*  Succinea  margarita,  Pfr. 

Hayti. 

Pupa  Jamaicensis,  Adams. 

Jamaica. 


ZOOLOGY.    MOLLUSCA.  183 

Pupa  pellucida. 

W.  Indies,  Yucatan. 

*  Pupa  Barbadensis,  Pfr. 

Barbados. 

On  the  authority  of  Bland,  quoted  by  Wallace. 

Pupoides  fallax,  Say. 

?  Bulimulus  nitidulus,  Pfr. 
United  States,  W.  Indies. 

Bulimulus  decollates,  L. 

Cuba,  Southern  Europe,  etc. 

This  species  appears  to  have  been  recently  introduced,  and 
is  not  mentioned  in  the  earlier  lists  of  the  Bermudian  pul- 
monates.  It  is,  however,  very  abundant  in  places;  we  found 
it  especially  numerous  along  the  roadside  near  the  Smith 
Parish  Church. 

*  Caecilianella  (Cionella)  acicula,  Mull. 

Central  Europe,  Madeira. 

Stenogyra  octona,  Chemn. 

Antilles,  Caracas,  Panama. 

Alexia  Bermudensis,  Ads. 
Pedipes  tridens,  Pfr. 

This  species  is  considered  by  Arango  (Contribution  a  la  Fauna 
Malacologica  Cubana,  p.  60)  to  be  identical  with  Pedipes  mirabilis, 
Miihlf.,  a  form  from  Cuba,  Jamaica,  Guadeloupe,  etc. 

Melampus  pusillus,  Gmel. 

W.  Indies. 

Melampus  Redfieldi,  Pfr. 

4. 

Melampus  coffea,  L. 

W.  Indies,  Mexico,  Guiana. 

Melampus  (Tralia)  cingulatus,  Pfr. 

Cuba,  Jamaica,  Porto  Rico. 

Truncatella  Caribaeensis,  Sow, 


184  THE  BERMUDA  ISLANDS. 

Cuba,  Jamaica. 

Truncatella  subcylindrica,  Gray. 

Cuba,  St.  Thomas,  Porto  Rico. 

?  Truncatella  pulchella,  Pfr. 

Cuba,  St.  Thomas,  Porto  Rico. 

Helicina  convexa,  Pfr. 

Onchidium  trans- Atlanticum,  n.  sp. 

NEW  SPECIES  OF  MOLLTJSCA. 
Octopus  chromatus.    (PL  15,  fig.  1.) 

Body  spheroidal,  somewhat  acuminate  behind,  and  im- 
pressed, but  not  furrowed,  ventrally ;  mantle  opening  extend- 
ing about  one-half  around  the  circumference  of  the  body,  and 
terminating  some  distance  below  and  back  of  the  eyes.  The 
head  not  much  narrower  than  the  body;  eyes  not  conspicuous, 
with  a  wart  above  each  ;  funnel  largely  free,  reaching  about 
half  way  to  the  base  of  the  web,  which  is  about  as  long  as  the 
body  and  head  combined. 

Arms  longest  as  1.  3.  2.  4,  although  possibly  the  second  pair 
outmeasured  the  third  pair  previous  to  contraction ;  slender, 
very  tapering,  and  exceedingly  attenuated  toward  the  apex 
suckers  fairly  large,  closely  placed,  and  in  regular  zigzag  alter- 
nation from  the  base,  contracting  with  a  quadrangular  outline. 

Body  granulated  posteriorly,  and  to  a  less  extent  in  the  re- 
gion of  the  neck.  Color  milky,  closely  blotched  or  speckled 
with  ochre,  giving  a  yellowish  appearance,  and  sprinkled  with 
brown. 

Length  of  specimen  about  nine  or  ten  inches. 

The  only  form  with  which  I  can  closely  compare  this  species 
is  the  Octopus  Bermudensis  of  Hoyle  (Challenger  Reports, 
Zoology,  XVI,  p.  94,  PL  II,  fig.  5).  which  is  described  from  a 
single  young  specimen,  measuring,  including  the  arms,  not 
more  than  two  and  a-half  or  three  inches.  It  differs  from 
this  form  in  the  extremely  tapering  and  attenuated  arms, 
their  relative  lengths  (1.  3.  2,  4  instead  1.  2,  3.  4),  and  in  the 


ZOOLOGY.    MOLLUSCA.  185 

disposition  of  the  acetabula,  which  are  in  zigzig  alternation 
from  first  almost  to  last ;  the  body  is  also  in  part  granulated, 
and  the  siphon,  instead  of  being  attached  for  nearly  its  full 
length,  is  largely  free. 

I  should  have  hesitated,  perhaps,  in  describing  this  as  a  new 
species,  distinct  from  0.  Bermuderws,  and  preferred  supposing 
that  the  characters  indicated  by  Hoyle  were  not  very  clearly 
marked,  or  that  they  possibly  represented  only  the  immature 
form,  but  Hoyle  distinctly  states  that  while  his  specimen  is 
probably  immature,  the  characters  are  so  well  marked  as  to 
safely  permit  of  their  recognition  as  typical  of  a  new  species 
(op.  cit.,  p.  95). 

Aplysia  aequorea.     (PI.  15,  figs.  2,  2a,  2b). 

Body  broadly  oval,  with  a  moderately  elongated  neck;  ten- 
tacles cylindrical,  slit  at  the  extremity ;  buccal  lobes  broad, 
infolded;  mouth  between  fairly  developed  lips;  aperture  to 
opercular  cavity  on  a  slightly  raised  papilla. 

Color  drab  or  greenish ;  exterior  surface  with  thin  black  an- 
nulations  and  irregular  markings,  which  are  few  and  scattered  ; 
the  inside  of  the  mantle-lobes,  as  well  as  the  cover  to  the  oper- 
cular cavity,  almost  free  of  blotches. 

Shell  narrowly-elongate,  somewhat  oblique,  and  calcareously 
lined  ;  longitudinally  radiated,  and  transversely  finely  striated. 

Length  of  animal  about  four  and  a-half  inches. 

A  single  specimen,  found  in  shallow  water  on  the  south  side 
of  Castle  Harbor,  opposite  Tucker's  Town. 

The  nearest  ally  of  this  species  is  probably  the  Aplysia 
occllata  of  D'Orbigny,  from  the  Canary  Islands,  or  the  common 
A.  dactylomcla,  from  the  eastern  Atlantic,  of  which  the  former 
is  by  some  authors  considered  to  be  only  a  local  variety  (Roche- 
brune,  Nouvelles  Archives  du  Mustum,  1881,  p.  264).  From 
both  of  these  forms,  apart  from  other  characters,  it  differs  in 
the  absence  of  the  heavy  ocellation,  and  from  A.  dactylomela 
in  lacking  the  purple  lining  on  the  mantle  margins.  From 
A.  oce&zta,  again,  it  is  clearly  marked  off  by  the  non-maculated 


186  THE  BERMUDA  ISLANDS. 

surface  of  the  interior  of  the  mantle  lobes  and  of  the  oper- 
cular  covering.  The  shell  in  the  Bermudian  form  is  compara- 
tively narrower  than  in  any  other  large  species  of  Aplysia 
with  which  I  am  acquainted,  and  wholly  different  in  outline 
from  that  of  either  of  the  two  species  above  referred  to.  I 
have  fully  satisfied  myself  on  this  point  through  an  examina- 
tion not  only  of  the  figures  furnished  by  Rang  and  D'Orbigny 
but  of  actual  specimens. 

Dobson,  in  a  communication  made  before  the  Linnsean  Soc- 
iety of  London  (Jour.  Linn.  Soc.,  Zoology,  xv,  p.  159,  et  seq., 
1881),  identifies  a  specimen  of  Aplysia  from  the  Bermudas 
with  the  A.  dactylomela,  and  describes  the  color  as  being  "  a 
rich  drab,  marked  all  over  with  circles  and  streaks  of  velvet 
black,  the  latter  most  abundant  on  the  mantle  covering  the 
shell  and  on  the  lateral  swimming  lobes.  The  shell  agrees  in 
all  respects  with  that  of  A.  dactylomela  as  figured  by  Rang, 
and  the  only  difference  observable  is  that  the  margins  of  the 
swimming  lobes  are  not  tinged  with  violet.  This  might  be 
accounted  for  by  supposing  that  such  a  fugitive  color  had  dis- 
appeared in  the  alcohol,  but  the  captor  does  not  remember  to 
have  seen  it  in  the  living  animal."  This  may  be  the  true 
A.  dactylomela  or  A.  ocellata,  but  it  is,  doubtless,  distinct  from 
the  species  above  described.  I  am  confirmed  in  this  supposi- 
tion by  the  examination  of  a  specimen  recently  collected  by 
Prof.  Dolley  in  the  Bahamas,  and  which  has  been  placed  in 
my  hands  through  the  kindness  of  Prof.  Leidy.  This  Baha- 
man  form  has  the  massive  ocellation  and  blotching  distinctive 
of  A.  ocellata  or  A.  dactylomela,  and  further  agrees  with  these 
two  species  (or  varieties)  in  the  form  of  the  shell.  The  stellate 
opening  to  the  opercular  cavity  appears  to  be  destitute  of  a 
papilla.  This  is  the  form,  probably,  that  Mr.  Dobson  received 
through  Surgeon  R.  Vacy  Ash. 

Deshayes  described  some  years  ago  an  Aplysia,  ocellated 
and  of  a  yellowish  color,  from  Guadeloupe  (Journal  de  Con- 
chyliologie,  2d.  ser.,  ii,  p.  140)  under  the  name  of  Aplysia 
Schrammii,  but  the  species  is  so  imperfectly  characterized  that 


ZOOLOGY.    MOLLUSCA.  187 

it  is  almost  impossible  to  determine  its  exact  relationships. 

Chromodoris  zebra.     (PI.  15,  figs.  3,  3a.) 

Animal  of  the  form  typical  of  the  genus ;  head  portion  con- 
siderably extended  and  expanded  in  motion  ;  caudal  portion 
moderately  elongated;  base  flattened;  mantle  beaded  im- 
mediately over  the  tail. 

Color  bright  blue  above,  variously  lined  and  streaked  with 
light  yellow ;  on  the  dorsal  surface  the  yellow  markings  are 
disposed  in  longitudinal  wavy  or  nearly  straight  lines,  one  or 
more  specially  prominent  lines  along  the  dorso-lateral  border. 
Sides  of  animal  irregularly  reticulated  or  angulated  with  yel- 
low markings;  under  surface  pale  blue,  bordered  with  faint 
yellow. 

Rhinophores  deep  indigo  or  black,  the  rhinophoral  aperture 
bordered  with  yellow ;  gills  12  or  13,  black,  bordered  with  yel- 
low, and  carrying  blue  cilia ;  under  surface  of  head  blue,  with 
yellow  spots. 

Length,  when  expanded,  three  and  a-half  inches. 

Three  specimens,  dredged  in  about  ten  fathoms  on  the  north 
side  of  Harrington  Sound.  I  dissected  one  of  these  and  found 
that  the  stomach  is  lodged  entirely  within  the  mass  of  the  liver. 
The  alimentary  canal  is  sharply  deflected  forward  (dorsally) 
beyond  the  buccal  or  oesophageal  tracts,  and  is  caught  up  in  a 
nerve  ring  proceeding  from  the  supra-oesophageal  ganglia. 

This  species  appears  to  be  third  or  fourth  of  the  genus  found 
in  the  western  Atlantic.  It  differs  clearly  from  the  C.picturata 
of  Morch  ( C.  Morchii,  Bergh,  Mas.  Godef.,  part  xiv)  and  C.  gonato- 
phora  of  Bergh,  two  West  Indian  species.  In  the  scheme  of  color- 
ing the  species  appears  to  be  nearest  to  Doris  pulcherrima  of  Can- 
train  e  (Malacologie  Mediterraneenne,  p.  57,  PL  3,  fig.  6,  ==  Ds 
Villafrancaf  of  Risso),  from  which,  however,  it  differs  in  a 
number  of  details,  such  as  the  number  of  gills,  etc. 

Onchidium  (Onchidiella)  trans  Atlanticum.     (PI.  15,  figs.  4,  4a.) 

Body  convex,  smoke  color  or  dark  olive ;  lighter,  dirty  or 
greyish-green  on  the  under  surface ;  pedal  disk  considerably 


188  THE  BERMUDA  ISLANDS. 

more  than  one-third  the  width  of  base,  yellowish-green  ;  mouth 
margin  papillose,  bunchy;  under  surface  obscurely  or  obso- 
letely  tuberculose;  dorsal  surface  closely  verrucose,  with  finer 
granules  interspersed  between  the  warts. 

Anal  aperture  immediately  beyond  the  extremity  of  foot, 
infra-marginal  to  a  raised  border;  respiratory  orifice  between 
the  anal  pore  and  the  apex  of  body. 

Length  about  three-quarters  of  an  inch. 

About  a  dozen  specimens,  found  in  a  rock  hollow  on  the 
north  shore  just  beyond  Wistowe,  near  Flatts  Village,  at  an 
elevation  of  about  two  feet  above  the  water. 

This  is,  as  far  as  I  am  aware,  the  only  species  of  Onchidium 
that  has  thus  far  been  recorded  from  the  western  Atlantic.  Its 
occurrence  is,  therefore,  of  considerable  interest  as  bearing 
upon  the  subject  of  geographical  distribution.  Nearly  all  the 
species  of  the  genus  are  confined  to  the  Eurafrican  and  Indo- 
Paoific  waters,  although  one  species  is  known  from  Arctic 
America,  one  from  the  California  coast,  and  one  from  the  west 
coast  of  South  America  (Bergh,  in  Semper's  Reisen  im  Archipd 
d.  Philippinen,  Land  Mollusks,  VI). 

The  Bermudian  species  appears  to  be  most  nearly  related  to 
0.  Carpenteri,  from  the  California  coast,  but  differs  from  it  in 
color.  The  positions  of  the  anal  and  respiratory  apertures 
differ  from  what  is  indicated  by  Stearns  (Proc.  Acad.  Nat.  Sci. 
Phila.,  1878)  to  exist  in  the  west  American  form,  although  agree- 
ing with  the  determinations  made  by  Bergh  for  manifestly 
the  same  species. 

Emarginula  dentigera.    PI.  17,  fig.  7. 

Shell  flattened,  scutiform,  broadened  posteriorly,  and  with 
the  apex  slightly  sub-central ;  surface  with  radiating  ribs, 
which  alternate  in  size — sometimes  two  smaller  ones  between 
each  pair  of  larger  ribs — and  project  (the  larger  ones)  prom- 
inently beyond  the  general  margin.  The  impressed  concentric 
lines  give  to  the  ribs  a  knobbed  appearance.  Fissure  fairly 
long,  narrow. 

Length  nearly  .25  inch. ;  height  .1  inch. 


ZOOLOGY.    MOLLUSCA.  189 

Emarginula  pileum.     PI.  17,  fig.  6. 

Shell  elevated,  with  the  form  of  a  Phrygian  cap ;  apex  largely 
posterior,  well  beaked;  radiating  lines  alternate,  deeply  im- 
pressed by  the  concentric  lines  of  growth,  and  appearing 
knobbed.  Fissure  moderately  long,  parallel-sided,  and  oc- 
cupying the  position  of  one  of  the  larger  ribs. 

Length  slightly  exceeding  a  quarter  of  an  inch;  height  .2  inch. 

Caecum  termes.    PI.  17,  fig.  5. 

Shell  arcuate,  gradually  increasing  in  size  anteriorly,  where 
it  is  somewhat  swollen ;  surface  longitudinally  costated,  the 
costse  appearing  slightly  rugose  near  the  swollen  base  through 
the  passing  of  the  lines  of  growth.  Mucro  distinct,  well 
excentric. 

Color  of  shell  yellowish  ;  surface  glossy. 

Length,  about  .1  inch. 

This  form  appears  to  be  fairly  abundant.  It  may  be  readily 
distinguished  from  most  of  the  other  longitudinal  costated 
species  by  the  very  nearly  equal  diameter  of  the  shell,  which  is 
only  slightly  swollen  basal ly. 

Chama  Bermudensis.     PI.  17,  fig.  1. 

Shell  thick,  ponderous,  sub-cordiform  ;  the  right  valve  con- 
siderably smaller  than  the  left,  but  yet  thicker  and  deeper 
than  in  most  Chamas ;  beak  of  left  valve  prominent,  spirally 
incurved;  ligamental  furrow  in  left  valve  deep,  arciform  ;  den- 
tal sulcus  broad,  moderately  deep,  and  supported  inferiorly  by 
a  prominent  plate  tooth. 

Muscular  impressions  elongated,  not  deep.  External  sur- 
face roughly  corrugated  by  the  lines  of  growth. 

Height  of  shell  (left  valve),  measured  to  the  top  of  beak, 
about  three  inches;  length,  measured  along  the  antero-pos- 
terior  axis,  2.3  inches;  thickness  of  single  valve  1.2-1.5  inch. 

Dredged  in  large  quantities  in  Harrington  Sound. 

Macoma  eborea.    PI.  17,  fig.  2. 

Shell  moderately  inequilateral,  truncated  in  the  lower  half; 


190   ,  THE  BERMUDA  ISLANDS. 

posterior  flattened.  Right  valve  with  widely  diverging  car- 
dinal teeth,  the  space  between  which  receives  the  double-tooth 
(grooved  medially)  of  the  left  valve;  lateral  teeth  in  right 
valve. 

Pallial  sinus  large,  extending  more  than  half  across  the 
shell ;  external  surface  (white)  concentrically  and  delicately 
lined  by  the  lines  of  growth. 

Length  of  shell  three-quarters  of  an  inch ;  height,  two- 
thirds  of  an  inch. 

Mysia  pellucida.    PI.  17,  fig.  3. 

Shell  thin,  convex,  ovally  orbicular;  the  umbones  mod- 
erately prominent;  no  lunule ;  hinge-line  linear,  a  single 
medially-grooved  cardinal  tooth  in  the  left  valve  (resembling 
Felania). 

Adductor  impressions  oval,  not  much  elongated.  Shell 
white,  nearly  smooth. 

Length  of  single  specimen  somewhat  over  a  half-inch; 
height  the  same. 

Cytherea  Penistoni,    PI.  17,  fig.  4. 

Shell  sub-trigonal,  the  beaks  prominently  elevated  ;  lunule 
cordiform  ;  the  dental  characters  normally  those  of  the  genus ; 
anterior  lateral  tooth  (left  valve)  triangular,  lamellar. 

Margin  of  shell  even  ;  pallial  sinus  broad,  directed  upwards, 
and  not  quite  reaching  the  centre  of  the  shell.  Lines  of  growth 
closely  set,  and  even.  Shell  covered  with  a  chestnut  epidermis ; 
interior  purplish. 

Length,  .6  inch ;  height,  .5  inch. 

It  gives  me  pleasure  to  name  this  delicate,  and  abundantly 
represented,  Cytherea  after  my  friend  Miss.  A.  Peniston,  of 
Peniston's,  from  whom  I  have  received  much  valuable  assistance 
in  the  preparation  of  my  material  illustrating  the  Bermudian 
fauna. 


ZOOLOGY.    MOLLUSCA.  191 

ON  THE  HELICOID  LAND  MOLLUSKS  OF  BERMUDA. 

BY 
H.  A.  PILSBRY. 

Through  the  courtesy  of  Professor  Angelo  Heilprin  I  have 
been  enabled  to  study  the  Bermudian  land  shells  collected  by 
the  party  conducted  by  him  during  the  past  summer.  Among 
them  were  examples  of  all  the  helicoid  species  which  have 
been  reported  by  previous  observers  from  the  island,  some  con- 
taining the  living  animal.  The  species,  with  the  exception  of 
a  number  of  artificially  introduced  European  shells,  are 
mostly  forms  well  known  from  various  West  Indian  localities, 
such  as  Helix  cereolus  var.  microdonta  Desb.,  H.  vortex  Pfr.  and 
others  ;  but  besides  these,  there  are  a  number  of  shells  peculiar 
to  Bermuda,  and  these  last  have  furnished  material  for  the 
following  notes. 

The  helicoid  species  confined  to  Bermuda  are  as  follows :  //. 
Eermudensis  Pfr.,  H.  Nelsoni  Bid.,  //.  Reiniana  Pfr.,  H.  circum- 
firmata  Redf.,  H.  discrepans  Pfr.  As  to  the  systematic  position 
of  these  forms  there  has  been  considerable  difference  of  opinion 
among  authors;  the  first,  //.  Bermudensis.  has  been  placed  in 
Camcolus  by  Von  Martens,  in  Hyalina  by  Clessin,  in  Zonites  by 
Bland ;  H.  Reiniana  has  been  considered  a  Patula  by  Pfeiffer, 
Clessin,  Tryon  and  Fischer;  and  //.  circumfirmata  and  dis- 
crepans have  been  placed  in  Microphysa  by  Von  Martens  and 
Binney,  in  Ilyalosagda  by  Clessin,  Tryon  and  others. 

Thus  it  will  be  seen  that  these  species  have  been  distributed 
into  several  genera  in  two  distinct  families.  Upon  examining 
the  soft  parts,  however,  I  find  that  all  have  essentially  the 
same  organization  and  without  doubt  belong  to  the  same 
genus. 

Dr.  0.  Boettger  proposed  in  1884,  for  the  lower  Miocene 
fossil  Helix  imbricata  Braun,  and  the  H.  Bermudensis  Pfr.,  the 
name  of  PcecMozonites.  He  gave  no  diagnosis  of  the  new 
group,  but  assigned  it  a  position  betwen  the  typical  Palrearctic 


192  THE  BERMUDA  ISLANDS. 

Zonitcs  and  the  American  groups  Zonyalina  and  Mordetia,  a  posi- 
tion which  the  anatomical  characters  prove  to  be  erroneous.1 

By  error,  the  genus  was  quoted  "  Poecilozonites  Sandbergcr  " 
in  the  Zoological  Record  for  1884,  and  this  error  was  repeated 
by  Tryon2,  who  gives  the  first  diagnosis  of  the  group  published, 
with  H.  Bermudensis  as  the  type  and  only  species.  We  may 
then  consider  the  H.  Bermudensis  Pfr.  the  type  species  of  the 
genus.  Whether  the  H.  imbricata  Braun  be  associated  with 
the  Bermudian  shells  or  not  is  a  point  still  to  be  settled.  The 
superficial  resemblance  is  marked ;  but,  as  the  history  of  the 
species  of  PcecUozonites  teaches  us,  "systematizing"  helicoid 
land  mollusks  by  the  shells  alone  is  the  merest  guess-work. 

The  fact  that  the  fossil  species  which  Dr.  Boettger  proposes 
to  unite  with  the  Bermudian  form  is  from  the  Lower  Miocene 
formation  of  Germany,  is  in  itself  no  great  objection  to  the 
view  that  they  are  congeneric;  for  no  fact  is  better  established 

1  «     *     *     *     Endlich  sei  noch  einer  nahen  Verwandten  der  Hocheimer  unter- 
miocaner  Helix  imbricata  Al.  Braun  gedacht,  die  Sandberger  bekanntlich  zu  Trocho- 
morpha    (Discus)   gestellt  hat.     Ich  gebe  die   Aehnlichkeit   zu;    aber  zur   Section 
Videna   H.  u   A.  Adams,  Discus  Alb.,  mochte  ich  die  betreffende  fossile   Art  nur 
ungern  stellen,  da  alle  mir  bekannten  lebenden  Arten  dieser  Gruppe  zum  mindesler 
einer  verdichter  basalrand,  der  oft  recht  erheblich  Helix-artig  umge^chlagen  ist  (wie 
z.  B  bei  Tr.  Merziana  Pfr.)  besitzen.     Viel  naher  liegt  daher  wohl  der  vergleich  der 
Helix  imbricata  mit  der  etwaskleineren,mit  zwei  brauncn  Bandern  gezierten  Hyalinia 
Bermudensis  Pfr.  von  den  Bermudas,  deren  Uebereinstimmung  in  alien  wesentlichen 
Charakteren  bei  directem  Vergleich  sofort  in   die  Augen  springen  diirfte.     Freilich 
kommen  wir  hier  fast  von  dem  Regen  in  die  Traufe,  da  die  systematische  Stellung 
dieter  lebenden  Art  selbst  noch  in  hohen  Grad  unsicher  ist,  was  ihr  Autor  durch  ein 
vorgesetzes  '  ? '  sehr  richtig  selbst  schon  angedeutet  hat.     Bei   Hyalinia  kann  sie 
unmojlich   bleiben.     Da  sie  meiner  Ansicht  nach  auch  nicht  in  die  indische,  indo- 
malayische   und   polynesische  gattung    Trochomorpha   passt,   so  diirfte  eine  eigene 
Gruppe  fur  Hyal.  Bermudensis  und  Helix  imbricata  zu  errichten  sein,  fur  welche 
ich  den  Namen  Poecilozonites  vorschlage,  und  die  ich  am  liebsten  zwischen  die  achten 
pnlaarktischen    Zonites    und   die    tropisch-amerikanischen    Gruppen    Moreletia   und 
Zonyalina  vorlaufig  als  Section   in  der  Gattung  Zoniles  Montf.  einreihen  mSchte,  bis 
die  Anatomic  der  lebenden  Art  eine  mehr  gesicherte  Stellung  in  System  an  die  Hand 
geben  wird."     O.  Boettger  in  Neues  Jahrbuch  fur  Mineralogie,  Geologie  u.  Palaeon- 
tologie,  1884,  ii  Bd.,  s.  139. 

2  Manual  of  Conchology,  2d.  series,  iii,  p.  19,  95. 


/( )OLOGY.    MOLLUSCA.  193 

in  malaco-geography  than  the  close  affinity  existing  between 
the  European  Tertiary  land  Mollusca  and  those  now  inhabiting 
the  West  Indies.1  To  explain  this  relationship  existing  be- 
tween two  regions  separated  by  the  whole  expanse  of  the 
Atlantic  various  theories  have  been  offered.  One  of  the  most 
plausible  is  that  which  bridges  the  Atlantic  by  an  ancient 
(Eocene,  early  and  Middle  Miocene)  continent — an  Atlantis, 
This  view  has  been  advocated  by  the  well-known  concholo- 
gist  Dr.  W.  Kobelt2  and' by  others. 

But  although  this  theory  explains  many  anomalies  in  the 
distribution  of  mollusks,  I  must  freely  confess  that  the  objec- 
tions to  it  seem  to  me  almost  insurmountable.  The  recent 
work  of  the  Challenger,  Blake,  and  other  deep-sea  explora- 
tions, all  tend  to  confirm  the  view  held  by  Guyot,  Dana, 
Agassiz  and  others,  that  the  great  oceanic  basins,  practically 
as  they  exist  to-day,  are  of  great  antiquity,  and  render  the 
existence  of  a  former  Atlantic  continent  with  any  considerable 
Western  extension,  highly  improbable. 

A  view  more  in  accordance  with  the  facts  with  which  we 
are  at  present  acquainted  seems  to  me  to  be  the  following:  It 
is  a  well  ascertained  truth  that  until  towards  the  close  of  the 
Miocene,  large  portions  of  Northern  Africa  as  well  as  Europe 
were  submerged ;  and  it  appears  probable  that  the  westward 
flowing  equatorial  current  of  the  Indian  Ocean  extended  across 
northern  Africa,  and  united  with  the  Atlantic  northern  equa- 
torial current,  which  now  flows  westward  from  northern 
Africa  through  the  Antilles  into  the  Gulf  of  Mexico.  This 
current  would  afford  a  means  of  transport  not  only  for  the 
free  swimming  embryos  of  marine  mollusks  (and  there  are  not 

1  This  affinity,  although  doubtless  very  great,  has  been  considerably  exaggerated. 
There  is,  for  instance,  no  warrant  for  referring  European  Tertiary  species  to  the  ex- 
clusively New  World  genera  Pleurocera,  Anculosa,  Tulotoma,  Mesodon,   Carinifcx, 
Afelantho,  and  others.     There  seems  to  have  been  no  infusion  of  European  Tertiary 
types  into  the  North  American  snail  fauna  east  of  the  Californian  region.     This  fauna 
is  truly  autochthonous. 

2  Nachrichtsblatt  d.  deutschen  Malak.  GeselL,  1887,  p.  147 


194  THE  BERMUDA  ISLANDS. 

a  few  forms  both  of  gasteropods  and  pelecypods  common  to 
the  Mediterranean  and  Gulf  Provinces),  but  also,  through  the 
agency  of  floating  materials,  trees,  etc.,  swept  from  rivers, 
land  mollusks  may  have  been  transported  across  the  Atlantic, 
just  as  they  have  been  carried  by  the  Gulf  Stream  from  the 
West  Indies  to  the  outlying  island  of  Bermuda,1  a  distance  of 
over  700  miles. 

A  further  development  of  the  same  idea  explains  certain 
peculiarties  in  the  distribution  of  species  common  to  the 
Pacific  and  the  Gulf  of  Mexico.  The  presence  of  Miocene  and 
Pliocene  deposits  render  it  certain  that  there  was  communica- 
tion between  the  Gulf  and  the  Pacific  across  the  Isthmus  of 
Panama  as  late  as  the  Pliocene.  And  a  portion  of  the  equa- 
torial current  probably  swept  directly  through  to  the  Pacific. 
Thus  it  is  likely  that  those  forms  common  to  both  sides  of  the 
isthmus,  will  prove  to  be  of  Atlantic  origin,  and  to  have  been 
distributed  westward. 

The  indigenous  Bermudian  mollusk-fauna,  marine  as  well  as 
terrrestrial,  has  undoubtedly  been  derived  wholly2  from  the 
West  Indies.  And  since  the  island  is  typically  oceanic,  "a 
solitary  peak  rising  abruptly  from  a  base  only  120  miles  in 
diameter,"  surrounded  on  all  sides  by  between  2500  and  3000 
fathoms  depth,  we  have  an  idication  here  that  land  mollusks 
of  many  families,  Helicidse,  Zonitidse,  Succinidae,  Pupidte,  Heli- 
cinidae,  even  Vaginulidse  (for  a  large  undescribed  species  of 
Vaginidus  exists  upon  the  island),  may  be  transported  far  out 
to  sea,  and,  in  all  probability,  by  the  agencies  mentioned  above. 

The  considerable  divergence  existing  between  the  various 
species  of  the  zonitoid  genus  peculiar  to  Bermuda,  Poecil- 
ozonites,  indicates  that  the  island  is  of  considerable  antiquity. 

We  may  define  the  genus  as  follows : 

1  See  Darwin,  Origin  of  Species,  6th  ed.,  p.  353.  Also  a  paper  by  Mr.  C.  T. 
Simpson,  On  the  Distribution  of  Land  and  Fresh-water  Shells  in  the  Tropics,  Conch. 
Ex.  ii,  p.  37,  50. 

2  See  on  this  point  the  chapter  on  the  "  Relationship  of  the  Bermudian  Fauna," 
ant.,  p.  88.  A.  H. 


ZOOLOGY.    MOLLUSCA.  195 

PffiCILOZONITES. 

Generic  characters:  Shell  helicoid,  subtrochiform,  depressed 
conic,  or  subdiscoidal,  perforate  or  umbilicate,  obliquely  striate, 
ornamented  with  radiating  zigzag  flammules  or  spiral  bands 
of  chestnut  color  on  a  lighter  ground  ;  whorls  numerous  (7-10); 
very  slowly  widening;  body-whorl  more  or  less  flattened  or 
compressed  below  the  usually  carinate  periphery,  not  descend- 
ing anteriorly;  aperture  more  or  less  irregularly  lunate;  peris- 
tome  simple,  the  columellar  margin  slightly  expanded  and 
thickened  with  a  white  callus  which  encircles  the  pillar  within. 
Animal  similar  in  form  to  Helix ;  foot  narrow,  short  posteriorly, 
scarcely  reaching  behind  the  shell,  and  without  longitudinal 
furrows  above  its  margin  or  caudal  mucous  pore ;  orifice  of  geni- 
tal ia  on  the  right  side  of  neck,  near  to,  but  not  under,  the  mantle; 
mantle  margin  simple;  jaw  like  that  of  JAmax,  very  thin, 
arcuate,  with  a  broad  blunt  median  projection  anteriorly ; 
radula  with  tricuspid  central  teeth  having  quadrate  basal 
plates,  the  central  cusps  projecting  beyond  the  anterior  mar- 
gins of  the  basal  plates,  the  side  cusps  rather  short,  with  well 
reflexed  cutting  points ;  lateral  teeth  similar  but  asymmetrical, 
lacking  the  inner  cusps ;  marginal  teeth  aculeate,  with  simple 
thorn-shaped  cusps  and  oval  basal  plates.  ' 

It  will  be  seen  by  the  above  definition  that  the  genus  cannot 
be  included  in  any  of  the  groups  with  which  its  species  have 
been  associated  by  authors ;  the  zonitoid  dentition  at  once  re- 
moves it  from  the  Helicidx,  and  the  absence  of  a  caudal 
mucous  pore,  the  more  anterior  position  of  the  orifice  of  the 
genitalia  and  the  coloration  of  the  shell,  separate  it  from 
Zoniies  and  its  subgenera. 

The  relationship  of  the  species  of  Poecilozonites  to  one  an- 
other is  shown  by  the  similarity  of  the  radula}  and  jaws,  and 
of  the  external  characters  of  the  animal;  in  the  shells, 
which  at  first  glance  seem  to  be  a  heterogenous  assemblage,  by 
the  callus  which  coats  the  columella,  the  compression  of  the 
whorl  below  the  periphery,  and  especially  by  the  color-pattern, 


196  THE  BERMUDA  ISLANDS. 

which  is  the  same  in  all  the  species,  consisting  of  zigzag  flam- 
mules  radiating  from  the  sutures.  In  P.  Bermudensis  the 
flammules  coalesce  into  continuous  bands  above  and  below 
the  periphery  in  the  adult;  but  an  examination  of  young 
specimens  reveals  the  same  pattern  that  is  found  in  P.  circum- 
firmata,  P.  Reiniana,  etc.  The  internal  spiral  lamella  of  P.  cir- 
cumfirmata  would  incline  one  at  first  to  separate  it  from  the 
other  species;  but  it  is  scarcely  of  generic  importance,  in 
view  of  the  fact  that  in  all  other  characters  the  species  is  very 
similar  to  P.  Bermudensis,  etc. 

The  following  analysis  shows  the  inter-relations  of  the 
various  species : 

A.  Base  of  shell  with  a  revolving  lamina  within. 

circumfir mains,  discrcpans. 

B.  Base  of  shell  without  lamina. 

a.  Aperture  rounded  below ;  umbilicus  wide       Reinianus. 

b.  Aperture  angulate  below ;  umbilicus  narrow 

Bermudensis,  Nelsoni. 

Pcecilozonites  Bermudensis,  Pfr.    (PI.  16,  figs.  E.  c.) 

The  typical  species  is  a  form  of  about  twenty-five  mm. 
diameter,  solid,  coarsely  irregularly  striate  and  acutely  car- 
iiiate  at  the  periphery ;  a  broad  chestnut  band  usually  encircles 
the  shell  above  the  periphery,  and  another  below  it,  but  these 
are  sometimes  absent ;  the  inner  whorls  of  the  spire  usually 
retain  traces  of  the  original  color-pattern  of  radiating  flames, 
and  the  base  in  young  examples  is  radiately  streaked  (PI.  16, 
fig.  E).  The  base  is  convex,  and  not  indented  around  the  nar- 
row and  deep  umbilicus,  but  is  angulated  at  its  margin ;  the 
parietal  wall  is  generally  covered  by  a  shining  white  layer, 
with  which  the  interior  of  the  shell  is  lined.  Reeve,  Tryon 
and  other  authors  have  figured  the  shell  of  this  species. 

The  jaw  is  like  that  of  P.  circumfirmatus. 

The  radula  (PI.  16,  fig.  c)  is  rather  long.  The  central  teeth 
have  basal  plates  almost  as  broad  as  long,  the  median  cusps 
projecting  below  their  lower  margins,  with  well-developed 


ZOOLOGY.    MOLLUSCA.  197 

cutting  points ;  the  side  cusps  short,  attaining  about  the  mid- 
dle of  the  basal  plate,  and  directed  outward;  the  lateral  teeth 
are  similar,  but  lack  inner  cusps;  they  are  about  eight  in 
number,  and  are  followed  by  about  four  transition  teeth;  the 
marginals  number  about  fifty  on  either  side,  their  cusps 
become  more  slender  toward  the  outer  edge,  and  the  basal 
plates  shorter.  A  central  tooth,  with  five  adjacent  lateral  teeth, 
and  a  group  of  transition  teeth,  with  a  true  marginal  tooth,  are 
shown  in  the  figure. 

Helix  albella  of  Chemnitz  (not  of  Linnaeus)  and  H.  ochro- 
leuca  of  Pfeiffer  (not  Ferussac)  are,  I  believe,  synonymous  with 
this  species.  The  former  is  placed  in  Eurycratera  in  Pfeiffer's 
Nomenclator,  and  the  latter  has  been  compared  to  Pachystyla 
rufozonata,  a  form  somewhat  similar  in  characters  of  the  shell, 
but  belonging,  of  course,  to  a  distinct  group. 

Pcecilozonites  Nelsoni,  Bland.     (PI.  16,  figs,  j,  K,  L.) 

A  fossil  form,  differing  from  Bermudensis  in  its  much  greater 
size,  the  greater  number  of  whorls,  more  convex  base,  coarser 
striation,  impressed  sutures,  and  especially  in  the  peculiarly 
prominent  dome-shaped  upper  whorls.  These  are,  indeed,  so 
closely  coiled  as  to  resemble  a  specimen  of  P.  circumfirmatus. 
The  coloration,  imperfectly  shown  in  several  specimens  before 
me,  is  that  of  Bermudensis;  and  whilst  its  affinities  are  with 
the  latter  species,  I  regard  it  as  a  divergent  branch,  rather  than 
as  an  ancestor  of  that  form. 

As  has  been  observed  in  other  cases  of  species  approaching 
extinction,  and  probably  subject  to  some  decided  and  unfavor- 
able changes  of  environment  (in  this  case,  perhaps,  due  to  the 
comparatively  recent  subsidence  and  partial  submergence  of 
the  island*),  the  shell  exhibits  great  mutations  and  distortions 
of  form ;  sometimes  the  spire  is  elevated  conical,  sometimes 
much  depressed ;  frequently  the  planes  of  the  upper  and  lower 
volutions  are  not  parallel,  and  the  spire  is  consequently  canted 

*  See  Challenger  Report,  Narrative,  vol.  i,  p.  138. 


198  THE  BERMUDA  ISLANDS. 

to  one  side.    The  species  is  remarkably  large,  solid  and  roughly 
sculptured  for  a  zonitoid. 

Pcecilozonites  Eeinianus,  Pfr.    (PI.  16,  fig.  i.) 

This  heretofore  unfigured  species  is  discoidal  in  form,  widely 
umbilicate ;  the  umbilicus  about  one-third  the  diameter  of  the 
base, and  exhibiting  all  the  whorls;  the  apical  whorl  is  smooth 
and  whitish ;  the  following  whorls  are  quite  convex,  with  deep 
sutures,  brownish,  very  prettily  zigzagly  flammulate  with 
chestnut  color,  like  many  of  the  species  of  Patula.  The  body- 
whorl  in  adult  examples  is  rounded ;  the  base  concave  around 
the  umbilicus,  and  the  general  aspect  that  of  Patula. 

The  jaw  is  like  that  of  P.  circumfirmatus. 

The  radula  (PL  16,  fig.  D)  is  similar  to  that  of  P.  Bermud,emis 
except  in  the  following  points :  the  cusps  are  larger,  with  much 
more  widely  reflexed  cutting  points ;  the  perfect  lateral  teeth 
are  seven  on  either  side;  the  change  to  marginals  is  quite 
abrupt,  as  there  are  but  two  real  transition  teeth  ;  the  mar- 
ginals number  about  sixteen  on  each  side,  the  inner  six  or 
seven  of  about  equal  size,  the  outer  ones  rapidly  decreasing 
toward  the  edge.  The  basal  plates  are  longer  than  in  the 
other  species.  A  central  tooth  with  two  adjacent  laterals  and 
one  marginal  are  shown  in  the  figure. 

Poecilozonites  Eeinianus  Pfr.  var.  Goodei  Pilsbry. 

This  form  is  similar  in  coloration  and  texture  to  P.  Reinianus. 
It  is  more  broadly  umbilicated,  planorboid,  the  spire  flat,  or 
even  sub-immersed ;  whorls  six. 

Alt.  3,  diam.  10  mill. 

Among  the  Bermudian  shells  sent  to  Prof.  Heilprin  from  the 
U.  S.  Nat.  Mus.  were  a  number  of  this  variety,  which  seems  to 
me  distinct  enough  for  a  name.  The  types  of  the  variety  are 
No.  94,424  of  the  National  Museum  register,  collected  by  G. 
Brown  Goode. 

Poecilozonites  Bermudensis  Pfr. 

The  result  of  my  dissection  of  this  species  was  a  surprise  to 
me?  for  I  had  expected  the  same  form  of  genitalia  as  is  found 


ZOOLOGY.    MOLLUSCA.  199 

in  Zonites.  The  penis  is  rather  short,  convoluted,  thick,  the  vas 
deferens  inserted  at  its  termination,  is  rather  short.  The 
cloaca  is  large,  wide  ;  below  the  penis  there  is  a  long  club- 
shaped  sac,  its  base  dilated  where  it  enters  the  cloaca.  This 
is  proably  a  dart-sack,  although  the  specimens  examined  by 
me  contained  no  dart.  On  the  penis  near  its  base  arises  a 
duct,  which  uniting  with  another  arising  opposite  the  penis,  is 
continued  into  a  long  duct  coiled  around  the  vagina,  and  ends 
in  a  small  oval  bulb,  the  receptaculum  seminis  or  spermatheca. 
The  albumen  gland,  etc.,  offer  no  unusual  characters.  I  did 
not  dissect  out  the  ovo-testis.  My  specimens  were  quite  hard, 
having  been  in  strong  spirit. 

The  connection  of  the  duct  of  the  spermatheca  with  the  penis 
is  unique,  so  far  as  I  know,  in  the  Pulmonata,  and  suggests  the 
probability  of  self-impregnation. 

Mr.  W.  G.  Binney  has  kindly  called  my  attention  to  his  note 
upon  the  dentition  and  jaw  of  //.  Bermudensis  and  the  denti- 
tion of  //.  circumfirmata  in  the  Ann.  N.  Y.  Acad.  Sci.,  iii,  p. 
86,  105.  The  first  species  is  placed  by  him  with  doubt  in 
Zonites  with  the  remark  that  "  it  seems  to  belong  to  no  de- 
scribed genus."  H.  circumfirmata  is  left  in  Microphysa,  for  want 
of  a  better  place,  but  Mr.  Binney  points  out  the  fact  that  the 
species  belongs  to  the  Vitrinea  rather  than  to  the  Helicea. 

Poecilozonites  circumfirmatus  Iledfield  (PI.  16,  fig.  F). 

A  form  with  much  the  appearance  of  Hyalosagda,  a  group 
with  which  it  has  been  classed  by  some  authors.  It  is  a  deli- 
cate, subtranslucent,  yellowish-brown  shell,  marked  with  brown 
streaks,  spots  and  flammules ;  the  whorls  are  separated  by  mod- 
erately impressed  sutures ;  the  apex  is  like  that  of  P.  Reinianus  ; 
the  last  whorl  is  more  or  less  angulate  around  the  periphery, 
rather  flattened  below  the  angle,  then  convex,  indented  around 
the  narrow,  deeply  perforating  umbilicus ;  there  is  a  white  cal- 
careous deposit  around  the  columella,  inside,  as  in  the  other 
species,  and  an  acute  white  lamella  which  revolves  within  the 
base  near  to  the  periphery,  a  character  which  none  of  the  pre- 


200  THE  BERMUDA  ISLANDS. 

ceding  species  possess.  The  variation  in  form  is  very  great — 
specimens  more  elevated  than  my  figure  F  being  not  infrequent, 
and  these  are  connected  by  examples  more  and  more  depressed 
(fig.  G)  with  the  flattened  lenticular  form  called  by  Pfeiffer  //. 
discrepans.  This  extremely  depressed  variety,  now  figured  for 
the  first  time  (PI.  16,  fig.  H.),  cannot  be  considered  specifically 
distinct  from  the  P.  circumfirmatus. 

Jaw  (PI.  16,  fig.  B)  transparent,  very  thin,  arcuate,  with  blunt 
extremities  and  a  wide  obtuse  median  projection  below. 

Radula  (PI.  16,  fig.  A)  as  described  for  P.  Bermudensis,  but 
with  only  seven  laterals,  two  or  three  transition  teeth,  and 
about  twenty-eight  marginals.  The  marginals  have  longer 
basal  plates  than  in  P.  Bermudensis. 

Helix  (Microphysa)  hypolepta  Shuttleworth. 

Of  this  minute  form  no  diagnoses  or  figures  have  been  pub- 
lished, although  the  name  has  been  upon  the  lists  for  many 
years.  The  shell  was  apparently  unknown  to  Pfeiffer  except 
by  the  remarks  of  Shuttleworth,  who  says  under  his  diagnosis 
of  H.  minuscula  Binn. :  "  Altera  species  proxima,  sed  testa 
aperte  umbilicata,  et  anfr.  ultimo  basi  devio  distincta,in  insula 
Bermuda  oecurrit,  cujus  specimina  plurima  ab  am.  Bland  ac- 
cepi,  atque  H.  hypolepta  nominavi." 

The  shell  is  minute,  discoidal,  whitish,  subtranslucent  and 
shining,  with  wrinkles  of  increment  above,  nearly  smooth  be- 
neath. The  four  whorls  are  very  convex,  quite  gradually 
widening,  the  last  one  with  the  periphery  above  its  middle, 
the  lower  lateral  surfaces  sloping  somewhat  as  in  H.  vortex  Pfr. 
The  aperture  is  small,  not  very  oblique,  oval.  The  lip  is  acute, 
upper  and  basal  margins  quite  arcuate,  the  baso-columellar 
margin  slightly  expanded.  The  umbilicus  is  broad,  more  than 
one-third  the  diameter  of  the  shell. 

Alt.  1,  diam.  2J  mill. 

It  is  evidently  allied  to  H.  (Microphysa)  vortex  Pfr.,  but  is 
much  smaller,  flatter,  with  broader  umbilicus.  I  need  not 
compare  Zonites  minusculus  with  this  shell ;  a  glance  at  the  fig- 
ures will  show  at  once  the  difference. 


ZOOLOGY.     MOLLUSCA.  201 

Helix  kypolepta.  Shuttleworth,  Diagnosen  neuer  Mollusken, 
no.  6,  from  the  Bern.  Mittheil.,  March,  1854,  p.  129. 

The  group  Micropliysa,  in  which  I  have  placed  this  shell,  has 
been  a  stumbling  block  to  most  of  the  authors  who  have  rec- 
ognized it.  It  consists  of  small,  umbilicated,  thin,  hyaline 
shells,  with  sharp  lip  to  the  lunar-oval  aperture,  convex  whorls 
and  impressed  sutures.  There  is  little  in  all  this  to  separate  it 
from  certain  forms  of  Zonites  (Z.  minusculus,  for  example). 
But  the  Zonites  have  narrow  aculeate  marginal  teeth  to  the 
radula,  while  these  shells,  typified  by  //.  Boothiana  Pfr.,  have 
the  dentition  of  Patula.  The  marginal  teeth  are  low  and  wide, 
with  several  denticles. 


APPENDIX. 


NOTES  ON  THE  RECENT  LITERATURE  OF  CORAL 

REEFS. 


W.  J.  L.  Wharton.     "  Coral  Formations."     Nature,  Feb.  23,  1888. 

The  author  cites  a  number  of  submerged  atoll-like  banks  in 
the  China  Sea,  depressed  to  depths  of  30-60  fathoms,  on  the 
rims  of  which  the  corals  are  still  inactive  growth.  Of  such 
are  the  Tizard  Bank  (with  a  length  of  32  nautical  miles,  and 
a  depth  of  water  over  the  rim  of  4-10  fathoms,  and  in  the  cen- 
tre of  30-47  fathoms),  the  Prince  Consort  Shoal,  and  the 
great  Macclesfield  Bank,  the  last,  70  miles  in  length,  and 
covered,  in  its  deepest  part,  with  sixty  fathoms  of  water.  These 
are  given  as  evidences  of  banks  that  are  being  built  up  through 
coral -growth,  and  which  are  ultimately  supposed  to  reach  the 
surface.  But  the  author  gives  no  evidence  to  show  that  these 
banks  are  not  in  reality  banks  of  subsidence,  drowned  atolls, 
similar  to  what  Mr.  Darwin  considered  the  Chagos  Banks  to 
be.  The  fact  that  corals  are  still  growing  on  the  rim  in  the 
one  case  and  not  in  the  other,  does  not  affect  the  question. 

Capt.  Wharton  disputes  Mr.  Murray's  conclusion  that  the 
great  depth  of  atoll  lagoons  can  be  formed  through  simple 
aqueous  solution,  and  observes:  "but  the  fact  that  for  large 
areas  it  [the  surface  of  the  reef]  remains  awash,  and  must 
have  so  remained  for  ages,  seems  to  me  to  point  to  the  supposi- 
tion that  the  removal  of  matter  is  too  insignificant  to  account 
for  the  formation  of  deep  lagoon  channels  in  this  manner, 
though  doubtless  it  may  explain  the  shallow  pools  and  creeks 
found  in  all  fringing  reefs." 

J.Murray.     "Coral  Formations."     Nature,  Mch.  1,  1888. 

A  purely  theoretical  answer  to  the  objections  contained  in 


CORAL  REEFS.    APPENDIX.  203 

the  paper  of  Capt.  Wharton,  noticed  above,  relative  to  the 
formation  of  deep  lagoons  through  solution.  No  facts  bearing 
on  the  subject  are  given. 

G.  C.  Bourne.     "  Coral  Formations."     Nature,  Mch.  1,  1888. 

The  author  coincides  with  the  views  of  Capt.  Wharton  as  to 
the  inefficacy  of  solution  in  producing  deep  lagoons.  "  It  has 
seemed  to  me,  as  it  has  to  him,  that  the  solution  of  dead  coral 
rock  in  the  interior  of  a  reef  does  not  sufficiently  account  for 
the  formation  of  lagoons,  and  that  the  true  cause  of  the  atoll 
and  barrier  lagoons  surrounded  either  by  a  reef  which  is 
awash,  or  by  a  strip  of  low  land,  lies  in  the  peculiarly  favor- 
able conditions  for  coral  growth  present  on  the  steep  external 
slopes  of  the  reef."  The  favorable  conditions  are  supposed  to 
be  due  to  the  action  of  currents  on  coral  growths  [not  a  better 
food-supply],  currents  of  moderate  strength  "  not  so  strong  as 
to  dash  them  [the  corals]  to  pieces,  but  strong  enough  to  pre- 
vent deposition  of  sand.  Such  conditions  are  found  ever}^- 
where  on  the  external  slopes,"  where  the  "main  part  of  the 
current  flows  tangentially  around  the  obstruction,"  adds  to 
"  greatest  advantage  around  the  periphery  of  a  reef,"  and  forms 
a  ring-shaped  reef;  "  no  theory  of  solution  is  required  to  explain 
the  central  depression." 

Mr.  Bourne,  as  a  non-believer  in  the  theories  of  solution  and 
subsidence,  fails,  however,  to  explain  how  the  ring-form  was 
constructed  below  the  zone  of  coral-growth  ;  the  extension  of 
the  lagoon  far  below  this  line  remains  unaccounted  for. 

K.  Irvine.     "  Coral  Formations."     Nature,  Mch.  15,  1888. 

An  attempt  to  determine  the  rate  of  solution  of  lime-car- 
bonate in  the  sea.  From  experiments  made  on  the  genus 
Po rites  (coral),  using  sea- water  with  a  specific  gravity  of  1.02G5, 
and  a  temperature  of  from  70°  F.  to  80°  F.,  the  author  arrives 
at  the  conclusion  that  "dead  or  rotten  coral  exposed  to  sea- 
water  under  these  circumstances  is  soluble  to  the  extent  of  5  to 
20  ounces  per  ton."  For  further  computation  the  author  as- 
sumes a  reef  with  a  lagoon  already  formed,  half  a  mile  in 


204  THE  BERMUDA  ISLANDS. 

diameter.  "This  will  give  an  area  of  about  600,000  square 
yards,  and  supposing  the  water  to  be  3  feet  deep  and  only  one- 
sixth  part  of  this  to  be  in  actual  contact  with  the  dead  coral, 
we  have  100,000  tons  exerting  its  solvent  action.  This  would 
give,  were  the  sixth  part  of  the  lagoon  water  to  be  expelled 
arid  replaced  with  fresh  sea-water  at  each  tide,  and  taking  the 
solvent  action  at  only  10  ounces  to  each  ton,  an  amount  of  car- 
bonate of  lime  removed  equal  to  about  3000  tons  each  year." 

Mr.  Irvine  curiously  asserts  that  while  he  does  "not  insist 
that  such  an  amount  of  carbonate  of  lime  must  year  by  year 
be  removed  from  the  lagoon,"  he  yet  thinks  that  the  "  experi- 
ments show  that  the  carbonate  of  lime  so  removed  may  easily 
exceed  any  additions  to  the  lagoon  by  secretions  of  animals 
living  in  it,  or  by  coral  sand  carried  into  it  by  wind  and  waves 
from  the  outer  edge  in  the  same  space  of  time,  and  therefore 
I  think  the  balance  of  evidence  is  in  favor  of  Mr.  Murray's  ex- 
planation of  lagoon  formation." 

But  Mr.  Irvine  does  not  inform  us  on  what  grounds  he  as- 
sumes that  this  internal  waste  may  exceed  accumulation  or 
accretion  by  growth.  The  argument  is  of  that  nature  which 
assumes  that  a  "  large "  figure  can  accomplish  anything,  or 
cover  a  multitude  of  omissions.  The  removal  of  3000  tons  of 
material  annually  from  a  comparatively  small  basin  appears 
like  a  large  amount,  but  when  this  quantity  is  closely  scru- 
tinized its  vastness  largely  disappears.  A  ton  of  limestone, 
allowing  a  weight  of  150  pounds  to  a  cubic  foot,  is  the  equiv- 
alent in  a  general  way  of  15  cubic  feet ;  3000  tons  will  there- 
fore represent  45,000  cubic  feet  of  material.  This  amount  dis- 
tributed over  an  area  of  5,400,000  square  feet  (600,000  yards,  as 
assumed  by  Mr.  Irvine)  would  cover  it  to  a  depth  of  the  rlo  of 
a  foot,  or  the  TO  of  an  inch.  In  other  words,  this  TO  inch  rep- 
resents the  annual  waste  according  to  Irvine;  it  is  the  equiv- 
alents of  a  cubical  block  of  rock  of  36  feet  dimensions.  Whether 
this  amount  is  sufficient  to  satisfy  the  demands  of  the  "  solution- 
ists  "  or  not,  I  am  not  in  a  position  to  say ;  but  from  my  observa- 
tions of  the  waste  of  the  Bermuda-lagoon  shores,  and  the  organic 


CORAL  REEFS.    APPENDIX.  205 

accumulation  taking  place  over  the  floor  of  the  lagoon,  I  am 
positive  that  it  does  not  by  a  long  way  meet  the  case  of  these 
islands.  The  height  of  the  shores  in  the  Bermudas,  doubtless, 
permits  of  vastly  excessive  destruction,  and  the  conditions, 
possibly,  cannot  be  absolutely  compared  with  what  we  find  in 
other  coral  islands.  Nevertheless,  I  am  inclined  to  believe 
that  the  organic  accumulation  (sea-urchins,  shells,  corals,  For- 
aminifera)  alone  over  the  floor  of  the  lagoons  fully  covers  the 
quantity  demanded  in  the  computation.  Bourne  and  Wharton 
are  likewise  of  the  opinion  that  the  amount  of  accumulation  is 
in  excess  of  that  of  solution ;  the  observations  of  these  investi- 
gators were  made  on  low-land  reefs,  in  which  the  special  con- 
ditions of  the  Bermudas  were  wanting. 

J.  G.  Ross.     "Coral  Formations."     Nature,  Mch.  15,  1888. 

Also  an  attempt  to  determine  the  solubility  of  calcium  car- 
bonate in  sea-water.  Mr.  Ross  finds  that  a  specimen  of  Oculina 
varicosa,  one  of  the  hard  West  Indian  corals,  measuring  about 
8  square  inches  of  surface  (with  a  weight  of  16*3164  grammes) 
lost  by  solution  in  20  days  0'0748  gramme;  and,  similarly,  a 
specimen  of  the  porous  Madrepora  scabrosa,  from  the  Feejee 
Islands,  with  a  surface  of  16  square  inches,  and  a  weight  of 
21 '8540  grammes,  lost  in  a  period  of  30  days  0*1497  gramme. 
From  a  circular  lagoon,  four  miles  in  diameter  (or  with  a  super- 
ficial area  of  some  12  J  miles),  it  is  concluded  that  at  this 
rate  of  solution  there  would  be  removed  within  a  year  8472 
tons.  This  if  evenly  distributed  "would  give  a  thickness  of 
half  an  inch  covering  the  whole  area  of  the  lagoon." 

T.  Mel  lard  Reade  has  pointed  out  the  error  in  this  calcula- 
tion (Nature,  Apl.  5,  1888),  which  assumes  for  the  quantity  of 
lime-carbonate  removed  by  solution  125  times  that  which  is 
carried  by  the  proposition.  In  other  words,  the  removal  of 
8472  tons  from  the  floor  of  the  lagoon  in  question  would  only 
increase  its  depth  (per  annum)  by  the  ?lv  inch  instead  of  one- 
half  inch.  At  this  rate,  as  Mr.  Reade  points  out,  it  would  re- 
quire a  period  of  a  million  years  to  hollow  out  a  lagoon  of  60 


206  THE  BERMUDA  ISLANDS. 

fathoms  depth.  There  are  probably  few  geologists  who  will 
permit  such  a  long  period  for  the  formation  of  this  accessory 
structure  in  a  coral-reef.  And  if  the  lagoon  itself  is  so  ancient, 
how  old  must  be  the  structure  in  which  it  is  implanted  ?  I 
have  discussed  this  subject  on  pp.  57-59,  and  have,  I  believed, 
demonstrated  that  according  to  the  determinations  of  the 
quantity  of  organic  and  inorganic  lime-sediment  contained  in 
sea-water  it  would  require  a  period  of  100,000  years  to  build 
up  the  thickness  of  a  single  foot  from  the  oceanic  abyss.  In 
shallow  water,  on  the  contrary,  the  process  of  construction  may 
be  a  very  rapid  one. 

H.  B.  Guppy.     "  Coral  Formations."     Nature,  Mch.  15,  1888. 

The  author  defines  the  conditions  governing  the  form  and 
the  life  of  reefs  as  follows :  "  On  the  outer  side  of  a  reef  we 
have  the  directing  influence  of  the  currents,  the  increased  food- 
supply,  the  action  of  the  breakers,  etc.  In  the  interior  of  a 
reef  we  have  the  repressive  influence  of  sand  and  sediment, 
the  boring  of  the  numerous  organisms  that  find  a  home  on 
each  coral  block,  the  solvent  agency  of  the  carbonic-acid  in 
the  sea-water,  and  the  tidal  scour.  These  are  all  real  agencies, 
and  we  only  differ  as  to  the  relative  importance  we  attach  to 
each."  No  new  facts  bearing  on  these  points  are  given. 

G.  C.  Bourne.     "  The  Atoll  of  Diego  Garcia  and   the  Coral  Formations  of  the  Indian 
Ocean."     Nature,  April  5,  1 888. 

A  description  of  the  southernmost  atoll  of  the  Chagos  Group, 
with  considerations  bearing  on  the  structure  of  the  other  reefs 
and  coral  islands  of  the  Indian  Ocean.  The  main  facts  con- 
tained in  this  paper,  as  well  as  those  contained  in  the  more 
elaborate  article  published  by  the  same  author  in  the  Proc. 
Royal  Soc.,  XLIII,  1888,  are  discussed  in  the  body  of  this 
work.  Mr.  Bourne  finds  evidence  of  an  elevation  of  some  4 
feet  in  the  Diego  Garcia  reef,  and  hence  concludes  that  the 
fact  precludes  "the  idea  of  any  subsidence  being  in  progress, 
as  Mr.  Darwin  fancied  to  be  the  case  in  the  Keeling  atoll." 
The  raised  atolls — "  atolls  whose  dry  land  just  rises  above  the 
waves  and  submerged  banks  " — of  the  coral  formations  north 


CORAL  REEFS.    APPENDIXT  207 


of  Madagascar  are  considered  to  be  "  proof  that  atolls  are 
formed  in  areas  of  elevation,  and  if  the  facts  which  I  have 
already  stated  concerning  Diego  Garcia  are  of  any  weight,  it 
would  seem  that  most  of  the  coral  formations  of  the  Indian 
Ocean  mark  areas  of  elevation  rather  than  of  rest,  certainly 
they  are  not  evidence  of  subsidence."  That  the  last  move- 
ment in  the  region  may  have  been  one  of  elevation  need  not 
be  disputed  ;  and,  as  far  as  any  general  theory  of  coral  forma- 
tion is  concerned,  the  same  movement,  or  a  reversed  one,  may 
be  taking  place  to-day.  But  Mr.  Bourne  does  not  show  that 
the  characteristic  structure  of  the  islands  under  special  con- 
sideration was  not  formed  during  a  period  of  subsidence,  or 
that  no  subsidence  has  really  taken  place;  the  fact  that  ele- 
vation may  be  now  taking  place  in  no  way  precludes  the  pos- 
sibility of  an  antecedent  subsidence.  The  raised  marine  strata 
of  continental  areas  might  as  well  be  taken  in  evidence  of  non- 
submergence  or  subsidence.  It  would  indeed  be  difficult  to 
prove,  from  what  evidence  Mr.  Bourne  has  placed  before  us, 
that  Diego  Garcia  is  not  to-day  subsiding,  instead  of  rising, 
despite  the  positive  proof  that  is  given  of  a  recent  elevation  of 
four  feet.  Assuming  the  correctness  of  Mr.  Darwin's  hypothe- 
sis of  subsidence  I  fail  to  see  what  condition  would  be  brought 
about  by  a  change  of  movement  —  i.e.,  if  such  subsidence  as 
caused  the  formation  of  "  drowned-atolls  "  were  followed  by  ele- 
tion  —  other  than  that  which  is  presented  by  Diego  Garcia  and 
the  other  reefs  which  Mr.  Bourne  describes. 

Mr.  Bourne  does  not  believe  that  the  solution-theory  of  the 
formation  of  lagoons  is  tenable,  and  he  challenges  "the  state- 
ment that  the  destructive  agencies  within  an  atoll  or  a  sub- 
merged bank  are  in  excess  of  the  construction  "  (vid.  ant.,  note). 

R.  Irvine.     "  Coral  Formations."     Nature,  Apl.  26,  1888. 

The  author  furnishes  the  following  results  as  to  the  solubility 
of  different  coral  fragments  (and  other  limestones)  in  sea-water, 
in  grammes  per  litre,  for  an  exposure  of  12  hours:  dead 
Forties,  0'395;  coral  sandO'032;  Bermuda  harbor-mud  0'041  ; 
Isophyllia  dipsacea,  from  Bermuda,  0041  ;  Millepora  ramosa 


208  THE  BERMUDA  ISLANDS. 

(Bermuda)  0'03G ;  Madrepora  aspera  0'073 ;  Porites  clavaria 
(Bermuda)  0*093;  weathered  oyster-shells,  0*331 ;  crystallized 
carbonate  of  lime,  0123;  amorphous  carbonate  of  lime,  0'049. 
The  rate  of  solution  here  given  is  vastly  in  excess  of  the  results 
obtained  by  Mr.  Ross. 

J.  Murray.      "  On   the   Structure   and   Origin   of    Coral   Reefs   and   Islands."      Proc. 
Royal  Soc.  Edinburgh,  X,  1880. 

An  exposition  of  the  non-subsidence  or  accretion  theory  of 
the  formation  of  coral  structures.  The  author  thus  sums  up 
his  conclusions  (p.  517): 

1.  Foundations  have  been  prepared  for  barrier  reefs  and 
atolls  by  the  disintegration  of  volcanic  islands,  and  by  the 
building  up  of  submarine  volcanoes  by  the  deposition  on  their 
summits  of  organic  and  other  sediments. 

2.  The  chief  food  of  the  coral   consists  of  the  abundant 
pelagic  life  of  the  tropical  regions,  and  the  extensive  solvent 
action  of  sea-water  is  shown  by  the  removal  of  the  carbonate 
of  lime  shells  of  these  surface  organisms  from  all  the  greater 
depths  of  the  ocean. 

3.  When  coral  plantations  build  up  from  submarine  banks 
they  assume  an  atoll  form,  owing  to  the  more  abundant  supply 
of  food  to  the  outer  margins,  and  the  removal  of  dead  coral 
from  the  interior  portions  by  currents  and  by  the  action  of  the 
carbonic  acid  dissolved  in  sea-water. 

4.  Barrier  reefs  have  built  out  from  the  shore  on  a  foundation 
of  volcanic  debris  or  on  a  talus  of  coral  blocks,  coral  sediment, 
and  pelagic  shells,  and  the  lagoon  channel  is  formed  in  the 
same  way  as  a  lagoon. 

5.  It  is  not  necessary  to  call  in  subsidence  to  explain  any  of 
the  characteristic  features  of  barrier  reefs  or  atolls,  and  all  these 
features  would  exist  alike  in  areas  of  slow  elevation,  of  rest,  or 
of  slow  subsidence. 

The  above  constitute  the  main  propositions  of  what  is  fre- 
quently termed  the  "  Murray  theory  "  of  the  formation  of  coral 
structures.  These  have  already  been  discussed  in  the  chapter 
on  "  The  Coral-Reef  Problem,"  and  therefore  call  for  no  special 


CORAL  REEFS.    APPENDIX.  209 

consideration  in  this  place.  Mr.  Murray,  like  most  of  the 
authorities  who  reject  the  Darwinian  hypothesis  of  subsidence, 
gives  no  satisfactory  data  in  support  of  his  propositions  (e.g.,  1, 
3),  and  he  appears  to  be  satisfied  with  the  mere  possibility 
(doubtless  to  him,  probability)  of  the  correctness  of  the  substi- 
tute theory.  Nor  are  any  facts  given  to  indicate  that  sub- 
sidence has  not  taken  place,  although  it  is  apparently  con- 
sidered more  convenient  to  "  do  away  with  the  great  and 
general  subsidences  required  by  Darwin's  theory."  But  why? 
In  what  respect  is  a  long-continued  subsidence  more  difficult 
to  be  believed  in  than  an  equally  long  continued  elevation? 
Yet  Mr.  Bourne,  one  of  the  strong  upholders  of  the  non-sub- 
sidence theory,  affirms  his  belief  (vid.  ant.)  that  "  atolls 
are  formed  in  areas  of  elevation  "  and  that  "  most  of  the  coral 
formations  of  the  Indian  Ocean  mark  areas  of  elevation  rather 
than  of  rest " !  Is  the  question  then  reduced  to  one  simply  of 
elevation  or  subsidence  ? 

Mr.  Murray  informs  us  that  his  views  "  are  in  harmony  with 
Dana's  views  of  the  great  antiquity  and  permanence  of  the 
great  ocean  basin,  which  all  recent  deep-sea  researches  appear 
to  support."  It  is  a  little  difficult  to  see  just  how  they  are  in 
harmony  with  these  views,  and  apparently  they  are  much  less 
so  than  is  the  subsidence  theory.  Dana  himself  states  (Re- 
port Wilkes  Exploring  Expedition  ;  A.  J.  Science,  3d  ser.,  XXX, 
pp.  94,  97)  that  the  course  of  the  coral  islands  in  the  Pacific 
conforms  largely  "  with  the  axial  line  of  greatest  depression," 
and  that  the  deep-water  area  or  trough  which  extends  south- 
eastward from  Japan  through  the  Central  Pacific  conforms 
"  well  to  the  suggestion  of  the  Darwinian  theory."  I  fail  to 
see  how,  if  the  coral  growths  are  planted  either  on  ascending  or 
stable  areas,  the  condition  specially  agrees  with  any  theory  of 
oceanic  permanency.  I  should  rather  think  the  reverse,  for  per- 
manency in  the  ocean  would  seemingly  be  established  through 
progressive  subsidence.  Mr.  Murray,  however,  states  that  all 
the  volcanic  regions  which  we  know  have  in  the  main  been 
areas  of  elevation  and  we  would  expect  the  same  to  hold  good 


210  THE  BERMUDA  ISLANDS. 

in  those  vast  and  permanent  hollows  of  the  earth  which  are 
occupied  by  the  waters  of  the  ocean  (loc.  cit.,  p.  516).  But  in 
what  lies  the  evidence  for  these  assertions  ?  It  would  proba- 
bly be  as  difficult  to  prove  a  general  elevation  in  volcanic 
tracts  as  it  would  be  difficult  to  furnish  that  evidence  in  favor 
of  subsidence  in  coral  areas  which  the  opponents  to  the  Dar- 
winian hypothesis  demand.  Indeed,  it  is  well  known  that  by 
many  geologists  volcanic  tracts  are  considered  to  be  areas  of 
subsidence,  rather  than  the  reverse.  This  is  the  view  now 
held  by  the  foremost  Austrian  geologists,  like  Suess  and  Neu- 
mayr,  who  associate  the  great  crustal  fractures  or  depressions 
— the  "  sunken  basins  " — with  volcanic  phenomena.  While 
subsidence  may,  and  with  little  doubt  does,  initiate  volcanic 
outflows,  it  seems  reasonable  to  suppose  that  any  very  great 
extravasation  of  material  from  the  earth's  interior  will  produce 
subsidence,  except  in  so  far  as  this  subsidence  may  be  locally 
balanced  by  the  material  ejected.  Dana,  indeed  informs  us, 
from  a  study  of  the  deep-sea  soundings  of  the  "  Tuscarora  "  and 
"Challenger,"  that  the  region  of  the  great  island  of  Hawaii, 
"although  it  is  now  actively  volcanic  and  has  little  growing 
coral  about  it,"  has  seemingly  "  undergone  more  subsidence 
than  the  coral  reef  end  of  the  chain,  and  that  its  height  and 
steepness  of  submarine  slopes  are  due  to  the  fact  that  its  out- 
flows of  lava  have  kept  ahead  of  the  subsidence,  and  also  built 
up  nearly  14,000  feet  above  the  sea"  (A.  J.  Science,  3d  ser., 
XXX,  p.  101). 

H.  B.  Guppy.     "Notes  on  the  Characters  and  Mode  of  Formation  of  the  Coral-Reefs  of 
the  Solomon  Islands."     Proc.  Royal  Soc.  Edinburgh,  1885-86,  pp.  857-904. 

This  is  one  of  the  most  comprehensive  papers  dealing  with  the 
coral  formations  of  any  one  single  group  of  islands.  The  re- 
gion of  the  Solomon  Islands  comprises,  according  to  this  in- 
vestigator, all  three  forms  of  reefs — atolls,  fringing-reefs,  and 
barrier-reefs — and  thus  presents  special  advantages  for  the 
study  of  the  coral-reef  problem.  The  author's  main  conclusions 
may  be  briefly  summed  up  as  follows: 


CORAL  &EEFS.   APPENDIX.  211 

1.  Reefs  appear  at  the  surface  as  the  result  of  growth  at 
about  the  sea-level  or  through  upheaval. 

2.  The  numerous  detached  submerged  coral-shoals,  which 
represent  the  early  condition  of  reef-structures,  are  not  able  to 
raise  themselves  to  within  the  constructive  power  of  the  break- 
ers without  the  aid  of  a  movement  of  elevation.     Being  arrested 
in  their  upward  growth,  at  depths  varying  between  5  and  10 
fathoms,  according  to  the  exposed  or  protected  character  of 
their  situation,  they  form  flat  shoals  of  no  great  size. 

3.  Atolls  of  small  size,  i.e.,  a  mile  or  so  across,  do  not  as- 
sume their  characteristic  form  until  they  have  reached  the 
surface.      A  small  flat-topped  shoal  is  first  brought  by  up- 
heaval to  or  above  the  sea-level ;  lateral  extensions  or  wings 
grow  out  on  either  side,  so  as  to  ultimately  form  a  horse-shoe 
reef.     Such  a  reef  presents  its  convexity  against  the  prevailing 
surface-currents,  to  which  in  truth  it  owes  its  shape. 

4.  The  larger  atolls  have  probably  assumed  their  form  be- 
neath the  surface,  "since,  according  to*  the  principle  laid  down 
by  Mr.  Murray,  they  would   then  have  a  relatively  smaller 
periphery  for  the  supply  of  food  and  sediment  to  the  interior 
than  would  be  possessed  by  the  small  submerged  shoals  above 
described." 

5.  The  true  "growing  edge"  of  a  reef  is  the  seaward  slope 
which  extends  outward  between  the  depths  of  4-5  and  12-18 
fathoms;  where  this  submarine  slope  is  more  than  10°  or  12°, 
"  as  is  usually  the  case,"  the  sand  and  gravel  arising  from 
oceanic  degradation — which,  with  a  more  gentle  slope,  accumu- 
lates at  its  base — is  carried  far  beyond  the  depths  in  which  reef- 
corals  thrive.     In  the  case  of  reefs  possessing  a  gradual  sea- 
ward slope,  i.  e.,  less  than  5°,  the  lower  margin  of  this  band  of 
detritus  will  lie  within  the  zone  of  reef-building  corals,  and  in 
consequence  a  line  of  barrier-reef  will  be  ultimately  formed 
beyond  this  band  with  a  deep  water  channel  inside.     Succes- 
sive series  or  belts  of  barrier-reefs  thus  formed  may  be  brought 
to  the  surface  through  a  progressive  rise  of  the  sea-bottom. 

6.  Reef-building  corals  are  not  restricted  to  a  superficial 


212  THE  BERMUDA  ISLANDS. 

zone  of  100-120  feet;  under  favorable  conditions  "they  may 
thrive  in  depths  of  50  or  60  fathoms,  and  thus  we  can  readily 
explain  the  apparently  abnormal  depths  inside  some  atolls  and 
barrier-reefs." 

7.  Reefs  grow  out  on  their  own  talus. 

It  will  thus  be  seen  that  Mr.  Guppy  dissents  from  those  who 
hold  to  the  theory  of  subsidence,  but  it  can  scarcely  be  said  that 
his  facts  are  fully,  or  even  largely,  in  accord  with  the  substi- 
tute theory  of  Mr.  Murray ;  nor  can  they  be  said  to  be  opposed 
to  the  requirements  of  the  Darwinian  hypothesis.  Perhaps 
the  most  important  of  Mr.  Guppv's  generalizations  is  that  reef- 
building  corals  can  tbrive  at  considerably  greater  depths  than 
has  been  generally  supposed,  reaching  under  favorable  condi- 
tions to  fully  three  times  the  depth  of  the  commonly  accepted 
limit.  Indeed,  if  this  condition  can  be  proved  to  exist  it  would 
naturally  do  away  with  much  of  the  necessity  for  a  belief  in 
subsidence,  since  it  would  (or  could)  explain  one  of  the  most 
distinctive  features  of  coral  structures,  the  deep  lagoons  and 
channels.  But  the  evidence  on  this  point  is  of  a  very  unsatis- 
factory nature.  Sporadic  growths  of  reef-building  corals  may 
well  be  found  in  depths  exceeding  the  so-called  coral-zone,  but 
until  it  can  be  shown  that  anything  like  a  reef-development 
takes  place  in  this  greater  depth,  we  are  justified  in  restrict- 
ing the  coral-zone  to  the  narrow  limits  which  have  been  gen- 
erally assumed  by  naturalists.  Mr.  Guppy,  indeed,  informs  us 
that  "under  favorable  conditions,  reef-corals  may  thrive  in 
depths  of  50  or  60  fathoms"  (p.  903),  but  this  statement  seems 
to  rest  merely  upon  an  antecedent  statement  (p.  887)  that  "  off 
the  reef  of  Choiseul  Bay  I  [the  author]  did  not  seem  to  have 
reached  this  lower  limit  [of  coral  growth]  in  soundings  of  40 
fathoms."  And  does  this  indicated  depth  of  40  fathoms  rest — 
as  it  certainly  seems  to — on  the  fact  that  in  a  cast  of  31  fathoms 
the  arming  preserved  a  "  rounded  impression  of  the  size  of  a 
billiard-ball,  the  inner  surface  of  which  retained  the  prints  of 
small  cells  as  if  of  a  Porites"  (Ann.  Mag.  Nat.  Hist.,  June, 
1884,  p.  464)? 


CORAL  REEFS.    APPENDIX.  213 

Between  thriving  at  depths  of  50-60  fathoms  and  the  finding 
of  an  obscure  impression  at  31  fathoms  there  is  surely  a  vast 
difference.  But  Mr.  Guppy  himself  informs  us  ("  Coral  Sound- 
ings in  the  Solomon  Islands,"  Ann.  Mag.  Nat.  Hist.,  June,  1884), 
that  in  Selwyn  Bay,  on  the  west  side  of  Ugi  Island,  the  depth 
at  which  coral  thrives  is  between  20  and  25  fathoms  (p.  461) ; 
in  Port  Mary,  Santa  Anna,  the  limit  is  placed  at  20-30  fathoms, 
although  the  deepest  recognizable  impression  (of  an  Astraan) 
was  obtained  from  only  17  fathoms  (p.  461) ;  off  Onua  the 
"lower  limit  at  which  coral  thrives"  is  about  20  fathoms  (p. 
463) ;  while  off  the  northwest  coast  of  Balftlai  Island,  Bougain- 
ville Straits,  "a  depth  of  15  fathoms  apparently  represented 
the  lowest  limit  of  the  zone  of-corals  "  (p.  463). 

Mr.  Guppy's  own  observations  are,  therefore,  practically 
confirmatory  of  the  observations  of  nearly  all  other  investiga- 
tors who  had  preceded  him.  In  fact,  if  we  except  the  impres- 
sion obtained  at  31  fathoms,  they  are  seemingly  absolutely 
confirmatory ;  moreover,  the  impression  may  have  been  that 
of  a  dead  coral. 

Dana  well  remarks  ("  Corals  and  Coral  Islands,"  1872,  p. 
118)  that  "soundings  with  reference  to  this  subject  are  liable 
to  be  incorrectly  reported  by  persons  who  have  not  particularly 
studied  living  zoophytes.  It  is  of  the  utmost  importance,  in 
order  that  an  observation  supposed  to  prove  the  occurrence  of 
living  coral  should  be  of  any  value,  that  fragments  should  be 
brought  up  for  examination,  in  order  that  it  may  be  unequiv- 
ocally determined  whether  the  corals  are  living  or  not.  Dead 
corals  may  make  impressions  on  a  lead  as  perfectly  as  living 
ones." 

It  is  on  this  slender  basis,  if  it  is  a  basis  at  all,  that  Mr. 
Guppy  constructs  his  theory  for  the  formation  of  barrier-reefs 
(which  inclose  deep  channels)  and  his  explanation  of  the  deep 
lagoons  of  atolls.  Prof.  Bonney  has,  it  appears  to  me,  well  an- 
swered that  "till  Mr.  Guppy  can  produce  cases  of  growing  reefs 
at  depths  well  exceeding  25  fathoms,  isolated  instances  of  the 
occurrence,  at  such  depths,  of  living  corals  which  are  among 


214  THE  BERMUDA  ISLANDS. 

the  reef-builders  do  not  really  help  him ;  and  that  till  he  can 
do  this  he  is  only  supporting  hypothesis  by  hypothesis" 
(Nature,  July  4,  1889).*  The  same  objection  probably  holds 
to  any  inference  being  drawn  from  the  discovery  of  a  number 
of  reef-genera  (Stylophora,  Astrsea,  Pavonia,  Cycloseris,  Lepto- 
seris,  Stephanaria,  Psammocora,  Montipora,  Alveopora,  Rhoda- 
roea  in  depths  exceeding  30  fathoms  off'  the  Tizard  and  Mac- 
clesfield  banks,  as  reported  by  Bassett-Smith  (Nature,  July  4, 
1889).  At  all  events,  more  detailed  information  than  we  now 
possess  regarding  this  seemingly  important  find  is  needed  be- 
fore satisfactory  conclusions  can  be  based  upon  it. 

There  is  another  point  with  reference  to  the  existence  of 
what  might  be  called  the  second  or  deeper  zone  of  coral  growth, 
which  is  supposed  to  be  separated  by  a  barren  sand  area 
from  the  normal  zone  (100-120  feet),  upon  which  Mr.  Guppy 
is  not  very  clear.  It  is  assumed  that  the  sand  resulting  from 
oceanic  degradation  destroys  the  life  over  which  it  is  largely 
precipitated,  and  that  were  it  not  for  its  bad  influence  corals 
would  be  found  growing  on  the  deeper  sea-ward  slope  as  they 
are  found  growing' above.  The  first  part  of  the  proposition  is 
in  a  measure  doubtless  true,  but  the  second  does  not  necessarily 
follow ;  on  the  contrary,  the  fact  that  these  corals  are  practically 
never  found  in  the  "  barren  "  area  is  almost  positive  evidence 
against  the  truth  of  the  proposition.  Otherwise  we  should  find 
scattered  and  luxuriant  growths  just  as  we  find  them  in  the 
interiors  of  the  sand-swept  lagoons.  According  to  Guppy  the 
lagoons  and  lagoon  channels  of  the  Solomon  Islands  are  largely 
occupied  "by  sand  and  chalky  mud;  but  in  the  shallower 
portions,  and  especially  in  those  situations  which  are  near  the 
breaks  in  the  reef,  corals  thrive  in  great  profusion  "  (Proc. 
Royal  Soc.  Edinburgh,  1885-86,  p.  861). 

In  the  lagoon  of  Oima  the  individual  coral-colonies  are  de- 
scribed as  being  very  much  larger  than  they  are  on  the  outer 
slope  of  the  reef;  "  large  masses  of  Porites  ranged  from  10  to  16 

*  I  regret  that  up  to  the  time  of  printing  it  has  been  impossible  for  me  to  secure  a 
copy  of  the  new  edition  of  Darwin's  work  on  coral  islands,  edited  by  Prof.  Bonney. 


CORAL  REEFS.     APPENDIX.  215 

feet  in  diameter;  whilst  the  largest  masses  that  I  found  in  the 
wash  of  the  breakers  at  the  outer  edge  of  the  reef,  which  be- 
longed to  species  of  Coeloria  and  Micandrina,  measured  only  5 
feet  across"  (p.  890).  Surely,  with  such  evidence  before  us  it 
cannot  reasonably  be  supposed  that  there  could  be  such  an 
extermination  from  the  outer  slope,  if  reef-building  corals 
really  thrive  at  these  depths,  as  Mr.  Guppy  would  lead  us  to 
suppose. 

With  regard  to  the  formation  of  the  deep  lagoons  and  chan- 
nels and  the  actual  thickness  of  the  coral-made  rock,  Mr. 
Guppy's  own  views  seem  to  be  in  conflict.  The  author  ap- 
parently inclines  to  the  views  of  Murray  and  his  followers 
that  these  deep  bodies  of  water  are  after-formations,  and  that 
they  have  been  produced  through  steady  removals  of  material. 
As  factors  in  this  removal  he  cites  the  action  of  carbonated 
waters  ("solution  theory")  and  the  various  forms  of  organic 
degradation  (pp.  893-97). 

But  no  instance  is  cited  where  any  considerable  depth  of 
water  has  been  brought  about  in  this  way  ;  it  is  merely  the  as- 
sumed hypothesis  of  possibility.  On  the  other  hand,  we  are 
positively  informed  (pp.  878-79)  that  the  lagoon  of  the  Oima 
atoll  (which  measures  nearly  two  miles  in  its  longest  diameter), 
with  a  depth  of  some  20  fathoms,  is  filling  up  through  the  ac- 
cumulation of  sand  !  And  this  condition  exists  in  an  atoll 
which  has  seemingly  experienced  no  "upheaval  since  the 
commencement  of  its  growth." 

The  same  condition  prevails  in  the  case  of  the  Keeling  atoll, 
where,  as  Mr.  Guppy  informs  us,  "  the  lagoon  is  rapidly  filling 
up  with  sand  and  coral "  (Nature,  Jan.  3,  1889).  The  facts  are 
thus  clearly  opposed  to  the  theory  that  is  assumed. 

One  of  the  points  that  have  been  specially  insisted  upon  by 
the  opponents  of  the  subsidence  theory  as  being  destructive  of 
that  theory  is  the  supposed  thinness  of  the  coral-made  rock, 
and  much  stress  has  been  laid  upon  the  researches  of  Guppy  in 
the  Solomon  Islands.  This  subject  has  been  considered  in  the 
chapter  dealing  with  the  "  Coral-Reef  Problem,"  but  a  few  adU 


216  THE  BERMUDA  ISLANDS. 

ditional  remarks  are  here  necessary.  In  his  more  recent  pub- 
lication on  the  "  Solomon  Islands  "  Mr.  Guppy  informs  us  that 
the  thickness  of  the  coral  limestone  in  the  upraised  reefs  is  in  a 
general  way  between  100  and  150  feet,  and  that  he  never  found 
an  island  "  that  exhibited  a  greater  thickness  of  coral-lime- 
stone than  150  feet  or  at  the  very  outside  200  feet"  (p.  71) 
This  is  in  itself  an  important  observation,  but  it  is  just  what 
we  should  expect  to  find  in  a  region  of  elevation,  as  we  are  in- 
formed this  one  is.  Without  subsidence  I  fail  to  see  how,  on 
the  Darwinian  hypothesis,  a  coral  limestone  could  have  a 
greater  thickness  than  100-150  feet.  The  special  significance 
of  the  observation  lies  only  in  the  fact  that  the  same  thickness 
of  coral-rock  is  associated  with  what  is  assumed  to  be  a  raised 
atoll — namely,  the  island  of  Santa  Anna.  This  island  is  de- 
scribed as  being  nearly  circular  in  form,  with  a  length  and 
breadth  of  two  and  a  half  and  two  miles  respectively,  and  con- 
sisting "  of  a  central  basin  surrounded  by  an  elevated  rim  [100 
to  200  feet  in  height],  which  is  wanting  at  the  middle  of  the 
west  or  lee  side.  The  bottom  of  the  basin,  which  extends 
downward  to  about  100  feet  below  the  sea-level,  is  occupied 
by  two  fresh-water  lakes,"  the  largest  of  which  measures  about 
half  a  mile  in  length,  and  has  a  depth  of  18  fathoms  in  its 
deepest  portion.  The  highest  elevation  of  the  island,  a  vol- 
canic peak,  470  feet  in  height,  rises  from  the  rim  of  the  eastern 
border,  while  another  elevation,  of  160  feet,  is  found  in  the 
centre  of  the  depressed  basin. 

It  does  not  appear  clear  that  this  is  a  true  atoll ;  and  Mr. 
Guppy  himself  admits  that  the  island  differs  "  from  the  typical 
reef  of  this  description,"  although  agreeing  with  the  atoll-like 
structures  of  the  Solomon  group  ("Solomon  Islands,"  p.  113). 
It  is  manifestly  a  part  of  that  class  of  structures,  the  horse-shoe 
shaped  reefs,  which  "do  not  assume  their  characteristic  form 
until  they  have  reached  the  surface,"  and  which  the  author 
broadly  distinguishes  from  the  large  atolls,  which  have  proba- 
bly "  assumed  their  form  beneath  the  surface  "  (Proc.  Royal  Soc. 
Edinburgh,  1885-86,  p.  900).  "  A  small  flat-topped  shoal  is 


CORAL  REEFS.    APPENDIX.  217 

first  brought  up  by  upheaval  to  or  above  the  sea-level.  Lat- 
eral extensions  or  wings  grow  out  on  either  side,  so  as  to 
ultimately  form  a  horse-shoe  reef.  Such  a  reef  presents  its 
convexity  against  the  prevailing  surface  currents,  to  which  in 
truth  it  owes  its  shape  "  (loc.  cit.,  p.  900 ;  this  view  of  the  forma- 
tion of  atollons  or  horse-shoe  reefs  is  further  elaborated  in  Mr. 
Guppy's  paper  "Preliminary  Note  on  Keeling  Atoll,"  Nature, 
Jan.  3,  1889).  Such  are  seemingly  the  conditions  that  we  find 
on  Santa  Anna  Island,  but  the  examination  of  the  100-fathom 
contour  line,  which  closely  conforms  to  the  actual  bounda- 
ries of  the  island,  even  to  the  indentation  of  the  17-fathom 
Port  Mary — concerning  which  Mr.  Guppy  expresses  himself 
as  having  "  been  unable  to  obtain  any  satisfactory  explana- 
tion "  ("Solomon  Islands,"  p.  117) — proves  conclusively,  I  be- 
lieve, that  the  surface  exposed  above  water  is  merely  the  cor- 
respondent of  that  which  is  below  it,  in  other  words,  the  island 
has  grown  up  on  a  base  of  its  own  form,  which  base  is  seem- 
ingly a  breached  crateral  cone  of  a  volcano.  It  repeats  on  a 
larger  scale  what  is  still  presented  by  its  own  highest  elevation, 
the  eastern  volcanic  cone,  which  carries  "  a  small  circular  hol- 
low, between  100  and  150  yards  across  and  35  or  40  feet  in 
depth.  There  was  a  time  in  its  history,  when  the  present  sum- 
mit alone  appeared  at  the  surface  of  the  Sea  as  a  tiny  ring  of 
coral  reef,  capping  a  submerged  volcanic  peak,  the  remains  of 
which  still  exist  in  the  shallow  basin  on  the  highest  part  of 
the  island  "  (op.  cit.,  p.  113).  I  think  we  are  well  justified  from 
this  evidence  in  assuming  that  the  large  breached-ring  is  sim- 
ilarly only  an  upgrowth  from  a  larger  crateral  border,  upon 
which  the  small  cone  is  perched.  Mr.  Darwin  early  recognized 
the  possibility  of  such  a  structure,  and  he  guardedly  affirmed 
his  belief  that  under  suitable  conditions  a  "  reef  like  a  perfectly 
characterized  atoll  "  might  be  formed  over  the  rim  of  a  crater 
("  Structure  and  Distribution  of  Coral-Reefs,"  1842,  p.  89). 

It  is  therefore  in  no  way  surprising  that  the  thickness  of  the 
coral-made  rock  on  this  island  should  be  comparatively  slight, 
and  nowhere  exceeding  150  feet. 


218  THE  BERMUDA  ISLANDS. 

Mr.  Guppy  ingeniously  argues  from  the  character  of  the 
rock  which  in  many  of  the  islands  immediately  underlies  the 
coral-limestone,  and  which  in  certain  organic  and  mineral  feat- 
ures recalls  the  deeper  deposits  of  the  ocean,  that  the  amount 
of  elevation  in  the  region  has  been  very  great,  and  that  the 
coral  formations  are  planted  directly  upon  deep-sea  or  even 
abysmal  deposits.  Thus,  it  is  claimed  in  the  history  of  Santa 
Anna  Island  that  "a  submerged  volcanic  peak,  lying  at  a 
depth  of  probably  2000  fathoms  below  the  surface,  was  covered 
by  a  deep-sea  mud,  and  then  elevated  until  it  became  the  base 
of  a  coral  atoll,  which  has  been  subsequently  upheaved  to- 
gether with  its  foundations  to  a  height  of  nearly  500  feet  above 
the  sea"  ("Solomon  Islands,"  p.  113).  I  fail,  however,  to  see 
the  force  of  the  argument.  In  the  first  place,  it  is  well  known 
that  the  pelagic  organisms  which  contribute  their  remains  to 
the  deep-sea  deposits  are  largely — if  not,  indeed  almost  wholly- 
animal  forms  which  inhabit  the  superficial  zone  of  the  sea; 
likewise,  the  inorganic  substances  which  accumulate  at  the 
bottom — cosmic  dust,  disintegrated  pumice,  etc. — are  derived 
from  the  upper  regions.  Hence,  manfestly,  a  shallow  open-sea 
deposit  will  have  much  the  characters  of  the  deep-sea  deposits, 
except  in  so  far  as  we  should  expect  to  find  it  retain  the  special 
features,  faunal  and  lithological,  of  shallow-water  formations. 
These  are  said  to  be  absent  in  the  organic  deposits  immediately 
underlying  the  coral-limestone  of  the  Solomon  Islands,  and  it 
is  accordingly  concluded  that  they  represent  deep-sea  forma- 
tions. But  the  difficulty  is  not  removed  through  this  interpre- 
tation, since  even  if  they  are  deep-sea  deposits  their  elevation 
into  the  upper  zone  would  have  brought  them  within  the 
reach  of  surface  conditions.  And  yet  the  accompaniments  of 
these  conditions  seem  to  be  wanting  until  we  reach  the  corals 
themselves.  The  negative  character,  therefore,  gives  no  evi- 
dence as  to  the  depth  at  which  the  sub-coralline  deposits  were 
laid  down.  But  the  fact  that  no  coral  rock  is  found  at  any 
really  great  elevation  above  the  sea  is  sufficient  evidence,  it 
seems  to  me,  that  there  has  been  no  such  marked  elevation  as 


CORAL  REEFS.    APPENDIX.  219 

Mr.  Guppy  suggests,  otherwise  it  would  be  almost  impossible  to 
account  for  the  nearly  equal  altitude  (above  the  water)  which 
this  formation  holds  in  the  different  islands  of  the  island  group. 
Indeed,  the  fact  that  by  far  the  greater  number  of  coral-islands 
and  reefs  lie  practically  at  the  level  of  the  sea,  or  but  a  few  hun- 
dred feet  above  it  in  the  case  of  fringing-reefs,  is  an  almost  in- 
superable objection  to  the  theory  which  holds  to  the  formation 
of  atolls  through  elevation;  the  uniform  line  of  position  is 
opposed  to  any  law  of  chances  which  might  be  assumed  to 
govern  a  broad  elevation.  The  same  objection  naturally  does 
not  apply  to  a  theory  of  upgrowth  in  a  stable  area  any  more 
than  it  does  in  the  case  of  a  subsiding  one. 

Mr.  Guppy  has,  indeed,  himself  anticipated  some  of  the  ob- 
jections to  his  owrn  views,  but  it  appears  to  me  he  has  failed 
to  grasp  their  full  significance.  If,  as  it  is  claimed  by  the  au- 
thor, reef-building  corals  may  thrive  at  a  depth  of  40,  50,  or 
(>()  fathoms,  and  if  their  structures  are  planted  directly  upon 
deep-sea  deposits,  then  manifestly  the  thickness  of  the  coral- 
made  rock  should  be  very  much  greater  than  has  actually 
been  found  to  be  the  case. 

Mr.  Guppy  attempts  to  meet  this  difficulty  by  assuming  [the 
immediately  reversed  position]  that  reef-corals  will  be  usually 
confined  to  depths  of  less  than  20  or  30  fathoms,  and  that  the 
"  rapid  sub-aerial  denudation,  to  which  these  regions  of  heavy 
rainfall  are  subjected,  would  be  an  important  agency  in  the 
thinning  away  of  the  raised  coral  formations"  (Proc.  Royal 
Soc.  Edinburgh,  1885-86,  p.  890).  This  is  surely  begging  the 
question — indeed,  it  might  be  said,  it  is  abandoning  the  main 
proposition — since  in  the  feeble  development  of  the  coral-made 
rock  the  one  vulnerable  argument  against  the  Darwinian  hy- 
pothesis was  supposed  to  lie ;  it  is  in  this  fact  that  the  oppo- 
nents of  the  subsidence,  theory  have  intrenched  themselves. 
Yet  we  have  here  the  testimony  of  the  only  investigator  in  the 
premises  that  the  thinness  of  the  rock  in  question  is  probably 
not  as  thin  as  it  is  supposed  to  be;  indeed,  for  any  evidence 
that  has  been  brought  forward  to  the  contrary,  the  rock  may 


220  THE  BERMUDA  ISLANDS. 

have  been  very  thick.  In  his  review  of  the  question  of  great 
elevation  Mr.  Guppy  thus  expresses  himself:  "So  great  has 
been  the  sub-aerial  denudation  of  these  islands,  that,  although 
the  elevatory  movements  have  brought  up  to  our  view  deep-sea 
deposits  which  have  been  formed  in  depths  probably  of  from 
1000  to  2000  fathoms,  yet,  notwithstanding  this  great  upheaval, 
the  calcareous  envelopes,  or  ancient  reef-formations,  usually 
disappear  from  the  slopes  of  the  large  islands  at  heights  of  500 
or  600  feet  above  the  sea,  and  never  came  under  my  observa- 
tion at  elevations  much  over  900  feet 

"  Besides  the  testimony  afforded  by  the  stripping  off  of  the  cal- 
careous envelopes  from  the  higher  levels,  abundant  evidence 
of  the  great  degradation  which  these  islands  have  experienced 
is  to  be  found  in  the  exposure  at  the  surface  in  various 
islands  of  highly  crystalline  and  other  much  altered  igneous 
masses  (such  as  quartz-diorites,  quartz-porphyries,  gabbros, 
felspar-rocks,  altered  dolerites,  and  serpentines),  which,  accord- 
ing to  Professor  Judd  and  Mr.  Davies,  were  formed  and  also 
altered  at  great  depths,  and  could  only  have  been  exposed  by 
extensive  denudation.  Of  the  rapid  degradation  of  the  surface 
which  the  calcareous  districts  undergo  in  this  region  of  heavy 
rainfall,  there  can  be  no  doubt.  It  should  therefore  be  re- 
membered, when  examining  this  region,  that  although  in  post- 
Tertiary  times  it  has  been  an  area  of  great  upheaval,  which  a 
moderate  computation  would  place  at  not  less  than  12,000  feet, 
it  has  also  been  an  area  of  most  rapid  denudation"  ("  Solomon 
Islands,"  pp.  125-26).  After  this  admission  of  enormous  waste, 
the  argument  from  the  thinness  of  the  coral-limestone  loses  all 
force ;  nor  can  it  be  reasonably  claimed  that  the  waste  extended 
only  over  a  thin  and  upwardly-extended  capping  of  rock,  since 
Mr.  Guppy  assumes  for  one  of  his  important  conclusions  that 
barrier  and  other  reefs  grow  out  on  their  own  talus.  With  origi- 
nation in  a  great  depth  there  would  be  ample  opportunity  for 
such  outward  growth,  and  the  accumulation  of  vast  thicknesses 
of  rock.  And  how  would  rock  accumulated  in  this  way  differ 
from  rock  accumulated  through  subsidence?  And  if  great 


CORAL  REEFS.    APPENDIX.  221 

thicknesses  of  coral-made  rock,  whether  formed  in  the  one  way 
or  the  other,  have  been  removed  from  the  elevated  reefs  of  the 
Solomon  Islands,  wherein  lies  the  evidence  that  there  has  been 
no  subsidence  ? 

H.  B.  Guppy.     "  The  Solomon  Islands."     1887. 

"The  Coral-Reefs  of  the  Solomon  Islands."  Nature,  Nov. 
25,  1886. 

"Observations  on  the  Recent  Calcareous  Formations  of  the 
Solomon  Group  made  during  1882-84." 

The  principal  facts  contained  in  these  papers  bearing  upon 
the  coral-reef  problem  have  been  considered  in  the  preceding 
review  of  Mr.  Guppy's  paper  "  Notes  on  the  Characters  and 
Mode  of  Formation  of  the  Coral  Reefs  of  the  Solomon  Islands." 

W.  J.  L.  Wharton.     "  Masiimarhu  Island."     Nature,  Sep.  1,  1888. 

A  delineation  of  two  slopes  of  the  coral  reef  surrounding  the 
small  island  of  Masamarhu  (situated  in  the  Red  Sea,  in  Lat. 
1#°  49'  N.  and  Long.  38°  45'  E.),  as  determined  by  Captain 
Maclear,  of  H.  M.  S.  "  Flying  Fish."  This  is  an  important 
contribution  to  the  history  of  reef-structures,  since  it  places 
beyond  doubt  the  fact  that  the  seaward  slope  of  some  coral 
islands  is  very  abrupt,  as  earlier  determinations  had  reported. 
At  one  point  removed  about  375  feet  from  the  growing  edge  of 
the  reef  soundings  indicated  a  depth  of  1200  feet,  or  an  aver- 
age descent  for  this  portion  of  the  slope  of  some  72°.  At  a 
distance  of  1200  feet  the  depth  was  found  to  be  1300  feet. 
Beyond  this  point  the  seaward  slope  is  somewhat  less  abrupt, 
and  at  a  distance  of  about  1900  feet  a  depth  of  only  1500  feet 
was  found.  Even  this  is  a  steep  slope,  averaging  38°,  and 
fully  equal  to  the  slope  of  the  steeper  volcanic  cones;  the  first 
portion  of  the  descent,  on  the  other  hand,  far  exceeds  the  slope 
of  any  mountain-peak  with  which  we  are  acquainted,  except 
where  sheer  (so-called  "  vertical  ")  rock-precipices  are  presented. 
Coral  and  coral  sand  were  obtained  from  nearly  all  parts  of 
the  slope,  and  at  one  point  coral  limestone  was  struck  at  1300 
feet.  In  two  or  three  places  the  line  dropped  into  deep  and 


222  THE  BERMUDA  ISLANDS. 

narrow  ditches,  the  walls  of  which  on  both  the  inner  and  outer 
sides  were  very  abrupt,  rising  at  an  inclination  of  about  80.° 
One  of  these  ditches,  reaching  in  its  bottom  to  1200  feet,  has  a 
depth,  measured  by  the  height  of  the  outer  wall,-  of  upwards  of 
350  feet. 

The  facts  of  this  island,  so  far  as  they  go,  are  distinctly  in 
favor  of  the  subsidence  theory,  and  they  have  been  properly 
estimated  by  Prof.  Bonney  (Nature,  May  23, 1889).  Mr.  Guppy, 
on  the  other  hand  (Nature,  May  16,  1889),  sees  in  Captain 
Maclear's  sections  evidences  favoring  Murray's  views!  How 
they  favor  these  views  is  not  stated,  nor  do  I  believe  that  it 
would  be  easy  to  find  an}  confirmation  in  them  of  the  theory 
of  organic  upgrowth.  Of  course  it  can  be  assumed  that  out- 
ward growth  on  an  extended  talus  might  (under  special  condi- 
tions) produce  such  a  steep  slope,  but  this  is  far  from  proving 
that  the  condition  did  in  fact  exist.  Further,  we  should  still 
be  compelled  to  prove  that  any  such  large  talus  can  form  (and 
I  believe  Prof.  Dana  has  well  argued  that  it  cannot  readily 
form),  and  that  even  if  formed,  there  is  that  (vast)  outward 
growth  upon  it  which  has  been  assumed  by  Murray  and 
Guppy.  As  regards  his  own  special  views  of  the  formation  of 
barrier-reefs,  etc.,  Mr.  Guppy  finds  full  confirmation  in  the 
"ditches"  which  were  located  on  the  slopes  of  Masamarhu, for 
he  thus  expresses  himself:  "  The  '  ditches '  shown  in  these  sec- 
tions I  look  upon  as  indicating  the  formation  of  barrier-reefs 
at  considerable  depths,  and  as  giving  remarkable  support  to 
my  views  on  the  origin  of  these  reefs"  (Nature,  May  16, 1889). 
Mr.  Guppy  has,  indeed,  pointed  out  (in  a  very  unsatisfactory 
manner)  that  reef-building  corals  'may  thrive  at  depths  of  50 
or  60  fathoms  (300-360  feet),  and  that  barrier-reefs  and  atolls 
may  begin  to  build  up  frorn  'these  depths  (answering  the  diffi- 
culty with  regard  to  the  deep  lagoons  and  channels);  but  now 
we  are  suddenly  called  upon  to  assume  that  they  build  up  from 
of  a  depth  of  200  fathoms  (1200  feet) !  Surely  the  most  doubt- 
ful cannot  readily  object  to  a  theory  which  is  so  elastic  as  that 
of  coral  upgrowth. 


CORAL  REEFS.    APPENDIX.  223 

H.  B.  Guppy.     "  Preliminary  Note  on  Keeling  Atoll,  known  also  as  the  Cocos  Islands." 

Nature,  Jan.  3,  1889. 

In  this  paper  (letter  addressed  to  Mr.  Murray)  the  author 
presents  some  interesting  facts  pertaining  to  the  formation  of 
horse-shoe  shaped  atollons.  His  conclusion  may  be  briefly 
stated  :  "  that  wherever  a  coral  island  stems  a  constant  surface- 
current,  the  sand  produced  by  the  breakers  on  the  outer  edge 
of  the  reef  will  mostly  be  deposited  by  the  current  on  each  side 
of  the  island  in  the  form  of  two  lateral  banks  or  extensions, 
giving  the  island  ultimately  a  horse-shoe  form,  with  the  con- 
vexity presented  against  the  current." 

A  bank  may  then  be  "  thrown  up  across  the  mouth  of  the 
horse-shoe,  and  a  small  atoll  with  a  shallow  lagoonlet  is  pro- 
duced." Other  points  reached  in  Mr.  Guppy's  examination  of 
the  Keeling  atoll  are  that  "the  lagoon  is  rapidly  filling  up 
with  sand  and  coral  "  and  "that  the  outward  extension  of  the 
reef  is  effected,  not  so  much  by  the  seaward  growth  of  the 
present  edge  of  the  reef,  as  by  the  formation  outside  of  it  of  a 
line  of  growing  corals,  which,  when  it  reaches  the  surface  re- 
claims, so  to  speak,  the  space  inside  it,  which  is  soon  filled  up 
with  sand  and  reef-debris." 

Mr.  Guppy  prefaces  his  paper  with  an  appeal  to  the  shallow- 
ness  of  lagoons,  and  criticizes  our  exaggerated  notions  of  these 
structures.  On  a  true  scale  it  is  claimed  that  a  typical  lagoon 
(i  would  be  represented  by  a  film  of  water  occupying  a  slight 
hollow  in  the  level  mountain-top."  The  author  further  ex- 
presses himself  as  follows :  "  By  thus  grasping  these  facts,  we 
at  once  perceive  that  by  reason  of  our  failing  to  view  an  atoll 
in  relation  to  its  surroundings,  and  through  our  misconcep- 
tions of  its  dimensions,  we  have  been  led  to  introduce  a  great 
cause  to  explain  a  very  small  effect.  The  slightly  raised  mar- 
gins can  be  easily  explained  by  causes  dwelt  upon  by  Murray, 
Agassiz,  and  others.  No  movement  of  the  earth's  crust  is 
necessary  for  this  purpose.  The  mode  of  growth  of  corals,  the 
action  of  the  waves,  and  the  influence  of  the  currents,  afford 
agencies  quite  sufficient  to  produce  the  slightly  raised  margins 


224  THE  BERMUDA  ISLANDS. 

of  an  atoll."  It  is,  indeed,  hard  to  class  the  logic  of  this  argu- 
ment. Is  it  to  be  presumed  that  because  some  geologists  have 
exaggerated  notions  of  the  configuration  of  an  atoll  and  its  in- 
closed lagoon,  that  the  lagoon  does  not  exist?  And  if  it  really 
does  exist,  how  near  are  we  brought  to  an  understanding  of 
its  structure  by  the  simple  conception  of  its  being  a  thin  film 
of  water  perched  upon  the  summit  of  a  flat  mountain-top  ? 
The  depth  of  the  lagoon  still  remains  the  same,  and  so  does 
the  height  of  the  raised  border.  It  might,  indeed,  as  well  be 
urged  that  there  is  no  necessity  to  account  for  the  structure  of 
mountain-chains,  since  the  highest  of  them  are  mere  wrinkles 
on  the  earth's  surface,  corresponding  in  size  to  the  irregulari- 
ties on  the  rind  of  an  orange !  Comparisons  are  useful,  but 
they  are  not  explanations. 

Johannes  Walther.      "Die  Korallenriffe  der  Sinaihalbinsel."     Abhaiull.  d.  mathem. 
physisch.  Classe  der  Konigl.  Sachs.  Gesellsch.  der  Wissenschaften,  xiv,  1888. 

No  new  facts  tending  toward  the  solution  of  the  coral-reef 
problem  are  given  in  this  valuable  memoir.  The  coral-struct- 
ures described  are  mainly  fringing-reefs,  and  they  occur  in  a 
region  of  existing  or  recent  elevation.  The  author  calls  atten- 
tion to  certain  atoll-like  or  ring-formed  islets  which  are  found 
associated  with  the  fringing-reefs,  and  which  in  some  instances 
are  immediate  outgrowths  from  the  latter.  This  circumstance 
is  immediately  seized  by  Mr.  Bourne  (?  G.  C.  B. — Review  of 
Walther's  work  in  Nature,  Dec.  20,  1888)  as  another  instance 
"  added  to  the  many  now  accumulating  of  barrier  reefs  and 
atolls  being  formed  in  an  area  of  elevation."  Walther  gives 
no  data  regarding  these  islets,  except  as  to  form.  It  seems 
proper  to  ask  in  this  connection  :  Are  all  circular  or  crescen- 
tic  growths  of  coral  to  be  classed  as  atolls  ?  Are  fringing-reefs 
which  for  a  short  distance  leave  the  coast-line  to  be  classed  as 
barrier-reefs?  Are  the  dunes  and  sand-hills  of  the  continental 
areas  mountains? 

As  touching  the  question  of  the  formation  of  these  islets  in 
an  "area  of  elevation  "  it  is  interesting  to  note  that  Walther 
recognizes  a  local  subsidence  of  some  6  metres  at  the  southern 


CORAL  REEFS.    APPENDIX.  225 

end  of  the  Peninsula  (Ras  Muhammed),  or  almost  in  the  very 
region  of  the  islets  in  question.  Further  to  the  north,  on  the 
other  hand,  the  reefs  are  strictly  linear  and  conform  rigidly 
to  the  coast-line,  and  are  confined  within  the  10-fathom  line. 
In  the  region  of  the  islets,  opposite  to  the  points  where  subsi- 
dence is  supposed  to  have  taken  place,  the  depths  are  much 
greater. 

S.  J.  Hickson.     "  Theories  of  Coral  Reefs  and  Atolls."     Address  British  Assoc.,  1888. 

Some  points  contained  in  this  paper,  which  is  a  broad  re- 
view of  the  opposing  theories  of  reef-formation,  have  already 
been  noticed.  Prof.  Hickson  considers  himself  an  adherent 
of  the  views  of  Mr.  Murray,  but  feels  doubtful  about  two  points : 
(1)  "Whether  the  power  of  solution  of  sea- water  is  sufficient  to 
account  for  the  formation  of  lagoons,  and  (2),  whether  in  some 
cases,  such  as  the  eastern  part  of  the  Feejee  Archipelago  and 
the  Low  Archipelago,  the  theory  of  subsidence  may  not  be  the 
correct  one."  The  author  believes  that  from  the  evidence  of 
the  Great  Chagos  bank  alone  "the  subsidence  theory  breaks 
down ,"  but  he  gives  no  facts  to  support  this  position  beyond 
the  belief  that  the  banks  are  (or  ought  to  be)  rising  instead  of 
subsiding,  as  they  were  considered  to  be  by  Darwin.  The  all- 
important  fact  which  Darwin  pointed  out,  on  the  testimony  of 
Captain  Moresby,  that  the  rim  of  this  supposed  "  drowned  atoll," 
lying  at  a  depth  of  a  few  fathoms  beneath  the  surface  of  the 
water,  consisted  almost  wholly  only  of  dead  coral,  Prof.  Hick- 
son  believes  "  requires  re-investigation,"  because  "  it  is  difficult 
upon  any  theory  to  see  why  the  rim  only  nine  or  ten  fathoms 
below  the  surface  should  not  be  covered  with  live  coral."  I 
fail  to  see  why  this  assumed  fact  is  opposed  to  "  any  theory  " 
of  coral  growth,  except  the  one  which  has  been  advanced  or 
sustained  by  Murray,  Guppy,  and  Bourne.  While  it  is  ad- 
mitted by  both  Darwin  and  Dana  that  the  reef-building  zone 
extends  down  to  ,a  depth  of  20-25  fathoms,  it  is  well  known 
that  in  many  coral  regions  the  practical  limit  of  coral  develop- 
ment is  found  at  only  half  this  depth.  Thus,  during  the  cruise 


226  THE  BERMUDA  ISLANDS. 

of  the  Wilkes  Exploring  Expedition  the  anchor  of  the  "  Pea- 
cock "  was  dropped  [within  the  reefs  of  Viti  Lebu  and  Yanua 
Lebu]  sixty  times  in  water  from  twelve  to  twenty-four  fath- 
oms deep,  and  in  no  case  struck  among  growing  corals. 
Patches  of  reef  were  encountered  at  times,  but  they  were  at  a 
less  depth  than  twelve  fathoms  "  (Dana,  "  Corals  and  Coral  Isl- 
ands, 1872,  p.  116).  Alexander  Agassiz's  researches  off  the 
Tortugas  reefs  lead  to  the  conclusion  "  that  corals  do  not  thrive 
below  a  depth  of  from  six  to  seven  fathoms,"  and  the  same 
limit  of  growth  was  found  by  Louis  Agassi'z  along  the  whole  of 
the  main  reef  to  the  northward  "  ("  Three  Cruises  of  the  Blake," 
vol.  I,  p.  74, 1888).  Walther  found  dead  reef  (supposed  to  have 
been  brought  about  by  subsidence)  at  Has  Muhammed  at  a 
depth  of  only  10  metres,  or  30  feet  ("  Die  Korallenriffe  der  Sinai- 
halbinsel"  p.  465, 1888).  Why  then  should  the  observations  of 
such  a  careful  investigator  as  Captain  Moresby  be  called  into 
question?  It  seems  to  me  that  they  very  closely  agree  with 
the  theory  of  subsidence. 

H.  0.  Forbes.     "A  Naturalist's  Wanderings  in  the  Eastern  Archipelago,"  1885. 

The  author  describes  the  Keeling  atoll,  which  he  believes 
to  have  risen  through  elevation,  and  finds  reason  to  conclude 
that  the  lagoons  have  filled  in  materially  since  the  time  of  Dar- 
win's visit. 

J.  D.  Dana.     "  Origin  of  Coral  Reefs  and  Islands."  Am.  Journ.  Science,  Sd.ser.,  vol.  xxx, 

1885. 

An  elaborate  review  of  the  objections  raised  to  the  Darwin- 
ian theory,  and  a  statement  of  facts  in  support  of  said  theory. 
This  is  by  far  the  most  searching  analysis  of  the  divergent 
views  bearing  upon  the  theories  of  coral-reef  formation,  and, 
as  it  appears  to  me,  it  satisfactorily  meets  all  the  objections 
that  have  been  raised  against  subsidence,  besides  showing  the 
inadequacy  of  the  substitute  theory.  The  author's  main  con- 
clusions are  thus  stated  (p.  190) :  "  The  subsidence  which  the 
Darwinian  theory  requires  has  not  been  opposed  by  the  men- 
tion of  any  fact  at  variance  with  it,  nor  by  setting  aside  Dar- 


CORAL  REEFS.    APPENDIX.  227 

win's  arguments  in  its  favor;  and  it  has  found  new  support  in 
the  facts  from  the  Challenger's  soundings  of  Tahiti  that  had 
heen  put  in  array  against  it,  and  strong  corroboration  in  the 
facts  from  the  West  Indies."  The  main  points  contained  in 
this  paper  are  such  as  have  already  been  considered,  and  re- 
quire no  lengthy  discussion  in  this  place.  Prof.  Dana  is  em- 
phatic in  his  belief  that  subsidence  (preceded  by  elevation) 
was  the  condition  which  permitted  "  of  the  making  of  the 
Florida,  Bahama  and  other  West  India  coral  reefs,"  a  view  in 
which  lie  is  distinctly  opposed  to  Mr.  Agassiz.  The  evidences 
for  this  subsidence  in  a  comparatively  recent  period  are  found 
in  the  mammalian  remains  of  apparently  Quaternary  age 
which  have  been  discovered  in  Cuba  and  Anguilla,  and  which, 
from  their  special  characters,  point  to  a  former  connection 
between  these  islands  and  the  mainland.  The  belief  in 
a  connection  between  the  Windward  Islands  and  the  South 
American  continent  has  also  been  held  by  Cope  and  Pomel. 
Dr.  Supan,  in  reviewing  Prof.  Dana's  paper  (Petermanns  Mit- 
teilungcn,  vol.  32,  pt.  1,  Litteraturbericht,  p.  5,  1886),  criticizes 
the  views  relative  to  subsidence  in  the  Floridian  region, 
since,  it  is  claimed,  even  if  direct  connection  did  exist  between 
the  West  Indian  Islands  and  the  southern  continent,  there  is 
no  proof  that  this  connection  extended  northward  to  the 
North  American  continent;  and  he  further  denies — without, 
however,  giving  any  reasons  for  this  .denial — that  there  ever 
was  any  (Quaternary?)  connection  between  the  West  Indies 
and  North  America.  This  notion  is  probably  based  upon  the 
old  idea  (advanced  by  L.  Agassiz  and  Le  Conte)  of  the  making 
of  the  Floridian  peninsula,  in  which  no  movements  of  either 
elevation  or  subsidence  were  supposed  to  have  been  involved. 
Since,  however,  this  conception  has  proved  to  be  a  myth  there 
is  no  further  reason,  except  in  so  far  as  the  case  may  be  sup- 
ported by  fact,  to  adhere  to  the  old  views  of  continental  (or 
oceanic)  stability  in  this  region.  My  own  observations  have 
conclusively  proved  a  peninsular  uplift  as  late  as  the  Post- 
Pliocene  period,  and  extending  as  far  south  as  Lake  Okeecho- 


228  THE  BERMUDA  ISLANDS. 

bee.  But  I  am  by  no  means  convinced,  as  I  have  elsewhere 
stated  (chapter  on  the  "  Coral-Reef  Problem  "),  that  a  nearly 
simultaneous  subsidence  did  not  take  place  in  (and  form)  what 
are  now  known  as  the  Straits  of  Florida.  The  existence  of  such 
a  subsidence  Bruch  is  considered  likely  by  Suess  (Antlitz  dcr 
Erde,  vol.  I),  who.  has  paralleled  it  with  (supposed)  simi- 
lar occurrences  in  the  eastern  basin  of  the  Mediterranean. 
This  view  of  the  formation  of  the  deep  Gulf-channel,  I  must 
confess,  appears  to  me  far  more  captivating  than  that  which 
ascribes  it  to  the  wash  of  the  Gulf-current. 

But  I  believe  direct  evidence  pointing  to  (although  by  no 
means  proving)  a  former  connection  between  the  Floridian 
peninsula  and  the  mainland  to  the  south  is  not  wanting.  In 
a  paper  on  "  The  Value  of  the  f  Nearctic '  as  one  of  the  Primary 
Zoological  Regions,"  published  in  the  Proceedings  of  the  Acad- 
emy of  Natural  Sciences  of  Phila.  for  1882,  I  pointed  out 
certain  facts  in  favor  of  considering  the  lower  portion  of  the 
peninsula  as  a  part  of  the  Neotropical,  rather  than  of  the  Nearctic, 
realm;  more  recent  zoological  researches  have  still  further  de- 
monstrated the  correspondence  existing  between  this  southern 
fauna  and  that  of  the  tract  lying  to  the  south.  But 
more  significant  is  the  finding  of  the  large  assemblage  of 
mammalian  remains  which  have  lately  been  brought  to  light 
from  various  parts  of  the  peninsula.  These  have  been  deter- 
mined by  Dr.  Leidy  to  be  the  skeletal  parts  of  the  elephant, 
mastodon,  llama,  rhinoceros,  tapir,  Hippotherium,  the  sabre- 
tooth  tiger  (Machairodus),  Glyptodon,etc.  (Leidy:  Proc.  Acad. 
Nat.  Sciences  of  Phila..  1884-89).  Neither  the  sabre-tooth  nor  the 
Glyptodon,  both  of  which  are  so  closely  related  to  the  commoner 
South  American  forms  as  to  be  barely  distinguishable  from 
them,  have  heretofore  been  found  in  the  Southern  United 
States.  Of  course  they  may  yet  be  found,  and  indicate  a  pas- 
sage over  from  South  America  by  way  of  Mexico  and  the 
Southern  United  States.  But  the  great  abundance  of  these  re- 
mains on  the  Floridian  peninsula,  and  their  absence  either  in 
whole  or  in  part  from  the  Gulf  States,  are  facts  which,  so  far  as 


CORAL  REEFS.    APPENDIX.  229 

they  go,  point  to  a  former  direct  land-connection  across  what 
is  now  an  arm  of  the  Gulf. 

J.  D.  Dana.     "  Points  in  the  Geological  History  of  the  Islands  of  Maui   and   Oahu." 
Am.  Journ.  Science,  3d  ser.,  xxxvii,  1889. 

The  author  gives  the  results  of  artesian  borings  made  on 
Oahu  (Sandwich  Islands)  which  indicate  the  presence  of  coral- 
rock  at  depths  varying  from  500  feet  or  less  to  upwards  of  1000 
feet  beneath  the  level  of  the  sea.  In  Mr.  Campbell's  well,  west 
foot  of  Diamond  Head,  a  continuous  bed  of  coral,  505  feet  in 
thickness,  was  struck  at  a  depth  of  320  feet.  The  species  of 
coral  found  in  these  deep  rocks  not  having  been  determined, 
Prof.  Dana  holds  that  some  doubt  may  yet  be  entertained  as 
to  the  beds  in  question  affording  positive  proofs  of  subsidence, 
although  there  is  a  strong  probability  favoring  this  view.  It 
is  interesting  to  note  in  this  connection  that  in  the  deep  well 
above  noted  a  soapstone-like  rock,  20  feet  in  thickness,  was 
found  immediately  underlying  the  basal  bed  of  coral  at  a  depth 
of  1048  feet.  Is  this  the  correspondent  of  the  soapstone-like 
beds  which  Mr.  Guppy  found  at  many  points  underlying  the 
coral  limestone  of  the  Solomon  Islands,  and  which  that  in- 
vestigator considered  to  be  evidence  in  favor  of  the  view  that 
corals  began  to  grow  upward  from  great  depths?  This  point 
is  fully  discussed  in  the  review  of  Mr.  Guppy's  papers. 

R.  von  Lendenfeld.      A   review   of  Mr.  Bourne's   paper  on   the    Diego  Garcia   Reef. 
N.iturwissenschaftliche  Rundschau,  Oct.  13,  1888. 

The  author  finds  no  facts  either  in  this  paper,  or  in  the 
papers  of  Murray,  Agassiz,  and  Guppy,  which  are  opposed  to 
the  theory  of  subsidence.  He  justly  calls  attention  to  the  low- 
level  of  coral  islands  generally,  which  is  opposed  to  any  theory 
of  the  progressive  elevation  of  the  ocean  bottom.  The  great 
development  of  the  dolomite  reefs  of  southern  Tyrol  (of  the 
Rha^tic  period),  such  as  the  Langkofel,  are  cited  in  evidence 
against  the  assumed  non-existence  of  thick  coral  limestones  in 
any  of  the  older  geological  formations. 

It  is  important  to  note  in  this  connection  the  observation  by 
Suess  that  nowhere  in  the  Gosau  deposits,  nor  in  the  coralifer- 


230  THE  BERMUDA  ISLANDS. 

ous  be<ls  of  Cormons  (Eocene)  or  Crosara  and  Castel  Gomberto 
(Oligocene),  did  he  observe  any  evidence  of  the  existence  of 
massive  coral  structures,  such  as  might  be  strictly  compared 
to  the  modern  reefs.  (Antlitz  der  Erde,  ii,  p.  407,  1888.) 

A.  Geikie.     Presidential  Address  delivered  before  the  Royal  Physical  Society  of  Edin- 
burgh.   Proc.  Royal  Phys.  Soc.  Edinburgh,  viii,  1883-84. 

A  review  of  the  rival  theories  of  coral-reef  formation.  Prof. 
Geikie  gives  in  his  adhesion  to  the  views  of  Mr.  Murray,  but 
adduces  no  fact  which  is  inconsistent  with  the  theory  of  sub- 
sidence. 

J.  Rein.     "  Die  Bermudas-Inseln  und  ihre  Korallenriffe,  nebst  einem  Nachtrage  gegen 
die  Darwinische  Senkungstheorie."      Verhandl.   d.    erst,  deutsch.    Geographentags, 

1881. 

I  have  not  seen  this  paper,  but  the  facts  contained  in  it,  so 
far  as  the  Bermudas  are  concerned,  seem  to  be  the  same  as 
those  which  are  given  in  his  original  memoir,  and  which  are 
discussed  in  the  main  part  of  this  work. 

K.  Semper.     "Animal  Life  as  affected  by  the  Natural  Conditions  of  Existence."     1881. 

In  this  work  the  author  reviews  Ins  observations  on  the 
coral-structures  of  the  Pelew  Archipelago — to  which  reference 
is  made  in  the  chapter  on  the  "  Coral-Reef  Problem  " — and 
asserts  his  positive  conviction  that  the  evidence  obtained  at 
this  point  is  directly  opposed  to  the  theory  of  subsidence.  The 
principal  basis  for  Semper's  conclusions  is  that  we  have  here  an 
association  of  all  three.cl asses  of  reefs — atolls,  fringing-reefs  and 
barrier-reefs.  These  he  considers  to  have  arisen  in  a  region  of 
1  elevation.  Semper  has,  I  believe,  given  us  positive  proof  of 
elevation,  but  I  fail  to  see  how  this  elevation  in  any  way  pre- 
cludes the  possibility  of  a  subsequent  subsidence;  nor  can  I 
find  any  facts  in  the  description  of  the  islands  which  speak 
against  such  a  subsidence.  On  the  contrary,  the  author  him- 
self admits  that  a  change  or  arrest  of  movement  (of  elevation) 
has  taken  place  when  he  asserts :  "  The  facts  here  adduced 
suffice,  as  it  seems  to  me,  to  prove  that,  in  the  first  place,  a 
quite  recent  upheaval. must  have  occurred  ;  and  secondly,  that 
that  period  of  upheaval  must  have  passed  into  the  present  con- 


CORAL  REEFS.    APPE^SX^  231 


dit.ion  of  very  slow  elevation  or  absolute  rest  without  any  con- 
spicuous break  "  (p.  263).      If  we  assume  that  this  arrest  of 
movement,  passing  into  a  condition  of  absolute  rest,  had  still 
further  progressed  into  one  of  subsidence,  I  think  we  will  then 
be  able  to  understand  all  the  special  (and  apparently  antago- 
nistic) features  of  the  region  to  which  Prof.  Semper  refers,  and 
in  a  manner  much  more  satisfactory  than  is  offered  by  the  ex- 
planation of  the  distinguished  German  naturalist.     It  seems 
to  me  that  the  condition  here  is  almost  precisely  what  we  find 
in  the  Bermudas:  a  coral-made  land,  which  had  been  elevated 
to  some  little  height  above  the  sea,  undergoing  waste  and  de- 
struction through  subsidence.     This  phase  in  the  history  of 
Bermuda  is  so  clear  that  there  can  be  no  question  concerning 
it.     In  the  Bermudas  we  have  also  a  near-lying  reef  on  the  one 
side  (likewise  the  weather  side)  and  a  far-off'  reef  on  the  other, 
with  an  intermediate  body  of  water  of  some  50-60  feet  depth. 
But  Prof.  Semper  himself  gives  data  which  lead  one  to  sup- 
pose that  subsidence  has  in  fact  taken  place.     The  biting  out 
or  undercutting  of  the  limestone  plateau  to  which  he  calls  at- 
tention (p.  254),  and  which  may  be  paralleled  with  the  similar 
process  on   the  south  shore  of  the  Bermudas,  surely  argues 
much  more  strongly  in  favor  of  subsidence  than  of  elevation ; 
it  certainly  seems  impossible  for  a  rock   to  be  at  the  same 
time  building   up  and   breaking  down.      But  further,  Prof. 
Semper  informs  us  that  it  "  is  certain  that  the  enclosed  island 
of  Babelthuap  was  formerly  much  broader  than  it  now  is  " 
(p.  270).    This  condition  is  scarcely  compatible  with  any  theory 
of  elevation,  and  more  nearly  accords  with  the  assumption  of 
waste  through  oceanic  encroaches  permitted   by  subsidence. 
Indeed,  the  author  himself  seems  not  to  have  been  convinced 
that  there  was  no  subsidence,  since  he  asserts  that  "  we  are 
obliged,  under  all  the  circumstances,  to  assume  the  co-opera- 
tion of  some  other  force  besides  subsidence  when  endeavoring 
to  explain  the  peculiar  formation  of  the  northern  reef,  but  still 
without  wholly  excluding  the  effects  of  subsidence"  (p.  253). 

Prof.  Semper  rejects  the  hypothesis  that  the  lagoon-ring  of 
an  atoll  is  formed  through  accelerated  marginal  growth  (p. 
227) ;  he  attributes  the  lagoon-basin  to  decay  and  scour. 


PI  10 


sp 


Geo.S.HarTis&Sone  Lilh.Phi' 


Zoology  of  the  Bermudas. 


PL  11 


Oeo.S  Harris  &Sons  Litlx.Phila. 


Zoolo6y  of  the  Bermudas 


PI.  12 


Heilprin,  del. 


Zoology  of  th.e  Bermudas 


PL  13. 


Heilprin,  del 


Zoology  of  the  BerTn 


PI.  14 


Jeo.S  Harris  &SOM  I.nh  Phila 


Zoology  of  the  Bermudas  , 


PI  15 


Heilprin,  del. 


Zoology  of  the  Bermudas. 


PI  15 


Zoology  of  the  Bermudas. 


IK*-  o,T^ 

(UNIVERSITY 

V  --   o* 


PI  17 


3  b 


Geo.S'.Harris&Sone  Lim.Phil». 


Zoology  of  the  Bermudas 


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(415)  642-6753 
1-year  loans  may  be  recharged  by  bringing  books 

to  NRLF 
Renewals  and  recharges  may  be  made  4  days 

prior  to  due  date 

DUE  AS  STAMPED  BELOW 


MAR  0  5  1991 


Returned  i>, 


JAN  0  8  1991 


Santo  Cruz.  Jitnev 


50m-7,'16 


